Pathway to Japanese Literature

I

At the tip of Murō Misaki, amid desolate gray mountains, the Takiguchi Mine operated by Chūetsu Coal Mining Company had long maintained its workings. Over these past two or three years, it had shown remarkable vigor—the tips of its black tentacles unfurled five hundred feet underground now reached half a mile beyond the seabed's edge. Reserves of six million tons—with the majority of the company’s operations staked on this single coal mine, both people and machinery were thrown into a state of tension, and harsh, unrelenting activity continued day and night. Yet among all perils, this undersea mine stood one step closer to hell itself. The more the enterprise prospered, the more the subterranean void expanded, and with unparalleled certainty, danger mounted ever higher. Layer by layer, they peeled away that thin crust of life separating them from damnation.

It was in the cold early days of April—when the world had only just crossed into that month—that catastrophe struck Takiguchi Mine with a violence so bizarre in form that it could only be acknowledged in this realm verging on madness.
Above ground, remnants of the season clung as deep snow in mountain folds, and a bone-chilling northern sea wind raged gloomily all day long—yet five hundred feet below, the earth sweltered with geothermal heat.
There lay a world stripped utterly bare, not a thread to clothe it.
No sooner had a man—mud-caked up to his navel, pickaxe slung over his shoulder—passed by with eyes glaring white in the darkness, than a naked woman pushing a coal cart suddenly darted out, her waist wrapped in a scrap of kasuri cloth, wriggling like a fish.

Oshina and Minekichi were a newly formed couple born of this violent dark world.
As was common in every coal mine, the two formed a pair—the man took on the role of coal miner, the woman that of cart pusher.
The young pair had their own coal face.
There, in the darkness beyond the foreman’s watchful eyes, they remained perpetually enveloped in honey-thick shadows.
Yet in this world that permitted no exceptions, even their happiness could not last long.

It was a morning when a cold wind laden with mist from flowing groundwater blew strangely down to the very bottom of the vertical shaft.

After receiving the second work ticket, Oshina took an empty coal cart that had been lowered to the bottom of the winding station and returned down the long tunnel to Minekichi’s coal face.
The coal mine was, so to speak, a black, breathing underground city.
In the bright brick-lined square connected to the surface by two vertical shafts—where the ceaseless groan of pumps and ventilators tangled with engineers’ T-squares and supervisors’ booming laughter—the black city’s heart loomed. From there extended a single thick horizontal tunnel, so to speak the grand avenue of this urban plan.
The branch tunnels opening their mouths left and right corresponded to numbered east-west avenues, while the comb-teeth-like coal faces established in each branch tunnel were numbered north-south side streets.
As she moved from the main line to branch roads, switching several points to approach Minekichi’s coal face, Oshina’s steps grew lighter.

Oshina, who after encountering supervisors and engineers apparently out on patrol partway through the branch tunnels and not running into any other company men, crossed the final switch point, took a sharp curve, and rushed into Minekichi’s coal face.

In the dark tunnel, Minekichi was waiting as usual.
Leaping back from the coal cart that came barreling in, Oshina kicked the back of the cart and threw her supple body into the arms of the man blocking her path.
As she threw herself into his embrace and was held, Oshina—in a dreamlike state—watched the empty coal cart retreat alone into the darkness, its frame trailing a dim safety lamp that swayed unceasingly.

It was entirely a dreamlike state.

Later, that incident was investigated many times, and the woman herself pondered it repeatedly, yet despite the scene being seared vividly into her mind, it remained an insubstantial event, like a memory from a dream.

Oshina’s safety lamp, leaving behind the two embracing in darkness, receded while faintly illuminating the coal cart’s edge and swaying as though hesitating—but as that cart swiftly retreated near the inner coal face, it began shaking violently with a sharp *clang*, likely from a pickaxe lying on the rails there, and in an instant, the safety lamp slipped its nail and tumbled onto the tracks.

The safety lamps distributed to miners at Takiguchi Mine were, like those in any other coal mine, Wolf-type safety lamps.
The Wolf-type safety lamps were designed to prevent the dangerous exposure of naked flames—they could only be opened or closed using a magnet held by the watchman stationed at the vertical shaft’s entrance.
However, if handled carelessly—placed at an angle or damaged—safety could not be guaranteed.

In such ill-fated circumstances, Oshina’s safety lamp dangled from the rear of the coal cart. As the empty cart continued moving, complex air currents arose around its backside—inevitably stirring up the fine combustible coal dust that had until then lain settled on the ground.
It was entirely a mere trifle, but in that instant, all the ill-fated conditions had aligned—and there, the safety lamp, which until then had been a symbol of the couple’s happiness, suddenly precipitated an unforeseen disaster.

In that instant, the woman thought a hundred magnesium flares had been ignited before her eyes.
Before the sound came, an intense pressure struck her ears, face, and body with a sharp crack. Half-aware of what felt like countless mud pellets scattering across her face, she staggered back involuntarily.
Staggering yet already sensing flames licking across the four walls deep in the coal face, she frantically turned and dashed toward the branch tunnel entrance—but immediately realizing Minekichi—!—she whirled back to see him racing after her like a shadow, crimson flames blazing at his back.
The flames that had spread to coal blocks ignited swirling clouds of coal dust one after another, their intensity surging violently.
Oshina felt fleeting relief at the disordered footsteps behind her and the two stark shadows cast ahead on the ground, yet kept running frantically.
The figure behind suddenly fell with a thud—whether from tripping over a rail sleeper or something else.
Before her eyes glowed the electric light of the branch tunnel.

However, when Oshina tumbled out under that electric light, there the first tragedy arose.
As Oshina—having emerged into the branch tunnel—stumbled over the complex rail points there and was thrown forward while looking back, the supervisor who had rushed over upon hearing the explosion was already beginning to close the sturdy iron fireproof door installed at the entrance of the coal face she had just escaped.
Oshina, having narrowly avoided being sealed inside by mere seconds, instinctively looked around with relief—only now comprehending the terrifying situation.
The crucial man—Minekichi—still hadn't emerged.
Oshina sprang up like an arrow and sank her teeth into the supervisor's arm as he fastened the fireproof door's latch.
A violent slap seared Oshina's cheek like a brand.

“You idiot! What if the fire spreads?!”

The supervisor roared.
Oshina—vividly recalling Minekichi writhing beyond the iron door that had sealed him moments after her escape as if struck by lightning—lunged forward again without a word in desperate frenzy.

But she was immediately slammed against the tunnel floor by an engineer who rushed up behind.
When a workman arrived next, the supervisor ran off to fetch clay for sealing the fireproof door’s gaps.
In such situations, they feared fire spreading to other tunnels far more than one or two lives.
This remained an unchanging custom of coal mines past and present.

Before the burning pit, miners and pit women began to gather.
Everyone—each and every one of them—was naked and jostling against each other.
Only the engineer wore corduroy trousers.
Seeing Oshina—restrained in a frenzy by the engineer and workman—and realizing Minekichi was nowhere to be found at the scene, the people immediately grasped the situation and turned ashen.

An older man and woman rushed out.
They were Minekichi’s parents, who had been working in the adjacent coal face.
When the engineer slapped the father with full force, the man sat down silently right there without another word.
The mother suddenly went mad and burst into cackling laughter.
Oshina, who had been thrown onto the rails and lost consciousness, was lifted up by a miner who stepped forward.
For Oshina, whose parents had died, this miner was her only remaining blood relative—her brother Iwataro.

While lifting the woman, Iwataro cast a hate-filled glance toward the engineers, then was soon absorbed into the churning crowd.

The supervisor brought clay packed into a bamboo basket.
Next, two miners came carrying heavy bamboo baskets in the same manner.
The workman immediately took a trowel and began filling in the gaps of the iron door.

When foremen from other sections rushed to the scene with the pit chief who had learned of the emergency, the engineer and supervisor, while directing the workman’s sealing work, drove off the clamoring crowd.

“Get back to the coal face!”
“Start mining!”

The people who had been shouted at pushed the coal carts they had been transporting, adjusted their pickaxes, and reluctantly withdrew.
As the commotion was driven away, the faces of those remaining before the iron door gradually showed expressions of relieved ease.

The sacrifice was confined to one pit.
Moreover, once sealed in this manner, even the flames in that single pit would soon be deprived of oxygen and extinguish.
The coal face was, so to speak, like a well drilled horizontally into the coal seam; beyond the sealed iron door at its entrance, there wasn’t even a hole large enough for an ant to crawl out.

Soon, the sealing work was completed.
Since this moment was exactly 10:30 AM, the time of ignition was probably around 10:00.
Yet by the time the sealing work concluded, the fire had evidently spread completely through the burning pit. The iron door—sensitive to heat conduction—burned soundlessly, imparting an eerie warmth to those nearby. The clay smeared into its gaps gradually dried from the thinner areas outward, its color shifting as countless irregular fissures split upward like gecko tracks.

The engineers, workmen, and supervisor alike were driven by an uncanny dread and became peculiarly bitter.
When the petitionary policeman, who had rushed over upon hearing of the emergency, arrived guided by a clerk, the pit chief, spitting saliva in displeasure, led the policeman back toward the square’s office.
The foremen also led Minekichi’s father—who until then had been sitting motionless on the spot—away and withdrew in the same manner.

The Supervisor began directing the workmen to clean up the area. There was no further need for the burning pit until the fire was fully extinguished. More than anything, there was no way to even begin addressing it.

The progress of fire suppression was entrusted to the engineer’s assessment. In every coal face, a single thick iron ventilation pipe had been installed. The sole remaining engineer removed the packed clay from the gap above the iron door, severed the burning pit’s ventilation pipe at its junction where it joined an even thicker iron pipe in the branch tunnel, and commenced analyzing the hot gas violently expelled through the severed pipe’s opening under intense pressure.

From time to time, lines of cart-pushers steering coal carts rumbled along the rails as if suddenly remembering their duty.
Through air in the branch tunnels—stilled by the commotion’s aftermath—rose the crazed laughter of Minekichi’s mother from beyond the darkness, bubbling up like seething gas.

The pit square—gateway to the black underground city—had regained its ordinary stillness.
The Takiguchi Mine needed to yield a hundred thousand tons of coal before summer’s end.
Not a single minute’s delay across all operations could be permitted for any minor catastrophe.
From shadows gleamed foremen’s eyes while coal carts, cages, pumps, and ventilators persisted in motion with heightened sinister hush.
Yet within the office, the section chief lashed out in foul temper.

In the chaotic twenty minutes following ignition—how many coal carts had come to a halt in the branch tunnels, how many miners had dropped their pickaxes—the section chief was the first to calculate it all.
Next came calculating how many tons of coal had been lost inside the burning pit—but this remained an unknown quantity.
Unless they conducted an on-site inspection, they probably couldn’t even make a rough estimate.
Thereupon, one of the clerks was dispatched to check the fire suppression status.
Next, they had to determine who would bear direct responsibility for this damage and investigate the cause of the ignition.
The section chief ordered another clerk to bring the surviving woman, then turned directly to address the petitionary policeman—who had been standing pompously by his side like a mine bureau inspector—for the first time.

“Oh, it’s nothing serious, really.”

Truly, sealing away a single miner might not have been such a grave matter after all.
However, it was only at this moment that a truly grave matter arose.
It was that the clerk who had earlier gone to inquire about the fire suppression status returned shortly thereafter and reported that the engineer called Maruyama had been murdered by someone.

II

The engineer’s corpse lay in a corner of the branch tunnel, some distance from the fireproof door.
It appeared he had been attacked while inspecting the hot gas—the severed exhaust pipe from the burning pit hung suspended by wire from ceiling timbers on the tunnel wall directly ahead, and analysis equipment lay scattered across a step platform.

The corpse lay face down, and the dark liquid that had flowed from its head glistened on the ground.
A large wound had tangled the wet hair on the back of the head like a chestnut burr, leaving the mouth agape.
The murder weapon was found immediately.
A little ways from the corpse’s feet lay a rounded-corner coal block as large as a pickling stone, glistening wetly with blood.
When the section chief saw this, he immediately fell silent and looked up at the ceiling.
This was no cave-in.
Yet even without a cave-in, a wound of this magnitude could be inflicted.

At five hundred feet beneath the earth's surface, the air pressure was considerably high.
On the surface, even if someone were to jump from a thousand-foot height, their corpse would often remain largely intact.
But should one fall five hundred feet down the vertical shaft into the depths of the earth, they would be crushed beyond recognition.
This terrifying reality underpinned cave-ins—even small fragments falling through short distances could crush human fingers like eggs.
Those who understood this saw nothing suspicious about a single coal block serving as an adequate murder weapon.
The section chief immediately threw down the lifted weapon and turned his ashen face toward the supervisor.

The workman, who had been standing stiffly until now, spoke up for the first time.

“After things settled down a bit and Mr. Asakawa went out on his inspection round, I went to put away the tamping rod in the tool storage—but this happened while I was gone.”

Asakawa was the supervisor’s name.
The workman was called Furui.
Both men, still reeling from the initial shock of the fire when confronted with this new incident, had become terribly flustered and lost all composure.
However, it wasn’t just the two who lost their composure.
Even the section chief himself—who had always prided himself on his broad-mindedness—was inwardly quite flustered.

The burning pit remained confined to a single shaft.
Even so, before they could even grasp the extent of the damage to that problematic shaft, a valuable engineer had been murdered by persons unknown.
The section chief—who had long made his living in the ruthless coal mines where violence was commonplace—must have been thrown into disarray sooner than anyone, not so much because a person had been killed, but precisely because it was an engineer who had been murdered.

However, before long, a look of harsh resolve began to appear on the section chief’s face.

“Who on earth killed him?”
“Haven’t you managed to identify any leads here?”

When the petitionary policeman made a nonchalant remark,

“Leads?
“If you’re talking about leads, we’ve already got one.”

The section chief turned directly and said irritably.

“It’s this ignition incident—a miner was too slow to escape and got sealed inside the burning pit.”
“It’s a pity, but of course we couldn’t save him.”
“However, it was Engineer Maruyama who took the lead in carrying out that sealing operation.”
“Since Engineer Maruyama—the very man who did this—has been killed, you can see how a lead would present itself.”
“Well, even if we don’t have a clear lead yet, the scope of suspicion has been narrowing down overall.”

“That’s right.”
“There’s no doubt about it.”

The supervisor leaned forward and said.

The supervisor—a special operations unit directly under the company and its most loyal profit hound—worked subordinate to the section chief who served as surface operations boss, yet in this regard maintained shadowy influence no less formidable than that of the section chief who had come up through the engineering ranks.
The constable nodded deeply.
The supervisor continued.

“Besides, there’s no one these days—complete strangers—who’d stick their nose into something like this… It was Minekichi, wasn’t it?
“The miner from this coal face—”

When the clerk nodded, this time the section chief took over and said.

“Bring that one’s parents and the surviving woman to the office and keep them there.”
“Ah, there was also the woman’s brother, wasn’t there?”
“Bring that one in too and keep him there.”

“Anyway, investigate all of Minekichi’s relatives.”

The supervisor said.

As the constable and clerk disappeared into the darkness in a flurry, the section chief went up to the closed fireproof door of the burning pit and came to a halt, pressing close as if drawn to it.

The sealing method had proved effective, and it appeared the suppression of the fire inside the pit had progressed considerably; almost no heat remained before the iron door.
But if they were to hastily open it now, the smoldering fire would likely receive a fresh supply of oxygen and regain its strength once more.
The section chief clicked his tongue and said to the supervisor.

“Could you call Engineer Kikuchi from the Tateyama Mine? And once you’ve finished your inspection rounds, please come to the office as well.”

The Tateyama Mine was a sister pit of the same company, separated by a single mountain and located in the central section of Murō Cape. In addition to the dedicated engineers stationed there, Engineer Kikuchi—who at any time took full charge of both the Takiguchi and Tateyama pits, effectively holding the rank of chief engineer—was supposed to have been there since several days before. The supervisor leaped onto one of the coal carts that had just arrived and disappeared into the darkness.

When the crowd dispersed, silence descended once more.
No sooner had Minekichi’s mother’s laughter echoed from the horizontal tunnel beyond the darkness than the creaking of coal carts intermittently carried the clamor of something being noisily hauled away.
The foreman of the left branch tunnel brought a coarse mat and, following the section chief’s instructions, proceeded to cover the engineer’s corpse.

The workman stood before the severed ventilation pipe, fiddling with various aspects of the murdered engineer’s remaining tasks, when suddenly he straightened up.

“Section Chief. It seems some noxious gas has started leaking.”

“Can you tell?”
The section chief smirked.

“I can’t say I grasp the technicalities, but I can tell by the smell.”
“The fire seems nearly out, but its smoldering appears to be producing foul gas.”

The section chief approached the iron pipe but immediately frowned,

“Hmm, this won’t do. We need to connect it to the branch tunnel’s iron pipe and flush out this gas right away.”
“Right.”
“You can tell by the smell, huh?”
“Then you check periodically and keep an eye on how the gas is being discharged.”
“I’m going to question the miners now, but within that time Engineer Kikuchi should arrive as well.”

The workman began connecting the iron pipe.
The section chief left the workman behind and started walking.

In the office in the square, four suspects were already sitting under the watch of a constable and three foremen.

Oshina had changed into nightclothes without anyone noticing, her hair disheveled and face hidden as she leaned against the wooden wall paneling, wheezing through labored breaths that heaved her shoulders. Her brother Iwataro, his face and chest still smeared with mud, kept glaring at the section chief who entered while his solar plexus swelled and sank like bellows.

Minekichi’s father remained motionless, staring at one spot with eyes like those of a dead fish, while his mother—restrained by a foreman’s grip—twisted her face into distorted smiles at intervals and fidgeted without pause.

The section chief stood right in the middle of the four and silently looked around at the suspects.

“That’s all of Minekichi’s relatives accounted for.”

“Yes,” one of the foremen said. “The rest are all complete strangers.”

The office was divided into several rooms.
The section chief ordered the foreman to bring in the four suspects one by one, then returned to the adjacent room with the constable and settled into a rickety chair there.

Iwataro was called in first.

The section chief briefly signaled the constable with his eyes, then leaned forward and turned to face Iwataro. And perhaps thinking to bellow something in a loud voice, he seemed to hold his breath, but immediately changed his mind and began speaking in a comparatively gentle tone.

“Where did you go taking your sister after that earlier?”

“……”

“Where did you go?”

However, Iwataro remained seated facing the section chief, his face swollen and silent as an oyster.

The constable floundered and interjected from the side.

“Well, you see… this man and that woman were brought from the shed...”

The "shed" referred to the one in the miners' settlement outside the pit, reached by ascending the vertical shaft.
The section chief did not answer the constable and said to Iwataro.

“What I’m asking is whether you went straight to the shed after that.”

Then Iwataro finally raised his face.

“I went straight there.”

It was a curt reply.

“Are you sure?”

The section chief’s voice grew stern.
Iwataro remained silent and gave a small nod.

“Good.”

The section chief turned to the foreman beside him and said.
“For now, have this man wait in that room. Then go straight to the vertical shaft’s watch post and confirm exactly what time he left carrying the woman.”

The foreman immediately took Iwataro and left.

Next, it was Oshina’s turn to be summoned.
When the woman sat in the chair, the constable said to the section chief:
“We were supposed to question this woman about the cause of the ignition too, weren’t we?”
The section chief silently nodded and turned toward the woman.
“The fire started from the safety lamp, didn’t it?”
“……”
“The source of the fire was the safety lamp, wasn’t it?”
Oshina nodded weakly.
“Was it your safety lamp or your husband’s? Which one?”

“It was mine.”

“Then how on earth did it ignite? Explain in detail what happened at that time.”

Oshina did not readily answer this question.
But eventually, a single tear spilled out, and she began to speak in a hushed, faltering voice, still looking down.
How Oshina had recounted the events of that time—yet there was no need to recount that here.
Oshina’s testimony differed not one iota from what had already been described at the story’s outset.

When the woman’s confession concluded, the section chief adjusted his posture and began speaking.

“We’ll verify what you said about the fire’s origin at the scene later… But this is another matter. You claim your brother carried you back to the shed that day—are you absolutely certain of that?”

However, this line of questioning was unreasonable.
At that time, Oshina had been so distraught with terror that Iwataro had to carry her; thus, whether she had been taken straight back to the shed with Iwataro was something even she herself could not have remembered.
Yet from the section chief’s perspective, he could not help but regard both Oshina and Iwataro with suspicion.
Thereupon, the section chief sought to press his inquiry further.

But at that moment, the office door opened, and the foreman from earlier returned with the watch post guard.

The salt-and-pepper-haired guard wearing an ill-fitting standing-collar uniform looked sharply between Iwataro and Oshina at the doorway, then came before the section chief and spoke.

“It would be these two, correct?”
“Yes, indeed. They exited via the cage from around 10:20 to 10:30 AM.”

“What? They left before 10:30?”

“Yes, indeed. At that hour, only these two miners exited the pit, so I distinctly remember.”

“I see.”
“So from then until just now when they were brought here, they never went back down into the pit, correct?”

“Yes, there is no mistake about that.”
“The other guards are well aware of it too.”

“I see. Good.”

When the guard left, the section chief exchanged looks with the constable.

If we said “before 10:30 AM,” the sealing of the fire pit had been completed precisely at 10:30 AM—and at that time Engineer Maruyama was still very much alive. How then could Iwataro and Oshina, who had already exited the mine before 10:30 AM, have murdered the engineer?
With this, two of the four suspects had simultaneously escaped the circle of suspicion.
There were two left.

The section chief first detained Iwataro and Oshina in the waiting room, then summoned Minekichi’s father.

“You were taken away by the foreman of the left branch tunnel back then and went somewhere, weren’t you?”
“Where exactly had you gone?”

Then, the old miner with eyes like a dead fish furrowed deep horizontal wrinkles across his belly skin each time he spoke,

“Please ask Mr. Foreman about that,”
he said.

The foreman of the left branch tunnel was eating lunch in the cafeteria but was immediately summoned by the section chief’s order.

“You took this man away from the front of the fire pit back then, didn’t you? And where did you take him after that?”

“This old man,” the foreman answered with a laugh. “He had his legs give out back then. So I took him to the infirmary... When I went there earlier to get a straw mat, he’d only just started to sit up... Even the nurse was having trouble with him.”

“I see,” the constable interjected. “And after he was able to get up, we don’t know where he went.”

he turned directly to the section chief and,

“This guy stinks.”
“After all, I was the one who captured him loitering around the branch tunnel entrance with his deranged wife and brought him here.”
“Where have you been and what were you doing after leaving the infirmary up until now...”

“No, you’re mistaken.”

The section chief, who had been silent until now, suddenly spoke.

“I see.”
“We don’t know where he was from when he became able to walk until he was captured.”
“However…” He turned to the foreman and—

“He hadn’t gotten up yet by the time you went to fetch the straw mat, had he? So you went to get that straw mat intending to drape it over Engineer Maruyama’s corpse, didn’t you?”

“Yes, I did.”

Then, the section chief turned directly to the constable and,

“Engineer Maruyama was killed while this man was still paralyzed in the infirmary.”
“This man’s legs gave out at the fire pit entrance—that’s why he was taken to the infirmary.”
“After that, the engineer was murdered, and the foreman went to fetch the straw mat for covering the corpse.”
“Only then did this man begin to sit up in the infirmary.”
“Meaning when Engineer Maruyama died, this man was still paralyzed and relying on the nurse.”
“A man who can’t move his legs couldn’t have gone to the branch tunnels to kill anyone.”
“You see it now, don’t you?”
“Then we’ve found our culprit.”
“Bind that deranged hag properly.”

The petition constable jolted to his feet, clattered into the adjacent room, and attempted to bind Minekichi’s mother without a word of explanation in front of Iwataro and Oshina.

However, at this moment, something utterly bizarre occurred there.
This was an event that completely overturned the section chief’s deductions, which had until now been pursued with confidence.

It should be noted that Engineer Maruyama, who had been killed, was ordinarily extremely strict in his work.
As a result, he was feared by the miners and often avoided by the executives.
However, he was by no means the kind of person who would incur such strangely personal, desperate hatred that would lead to being killed.
Only this miner entombment incident was the first and only case that could have incurred such hatred.
There, the section chief had arrested all those likely to resent Engineer Maruyama over Minekichi’s entombment, interrogated them one by one, and now finally seemed on the verge of achieving his objective.
Moreover, the four suspects who should have harbored intense resentment toward Engineer Maruyama—for his role in Minekichi’s entombment alongside engineers and supervisors—had all been confined in the office regardless of whether their suspicions were cleared or not. Under the surveillance of constables and foremen, the investigation proceeded until now, when they encountered this bizarre event there. Not a single one had managed to escape during that interval.

Now, as for that incident—it was at the very moment when Minekichi’s mother had been identified as the culprit who had exacted revenge in her son’s stead and was about to be apprehended by the petition constable.
From the front of the office came a restless stir—then Supervisor Asakawa slid open the glass door and burst in.
And without so much as a glance at the room’s condition, he addressed the section chief while catching his breath.

“Engineer Koi has been killed.”

III

Indeed, those engaged in exceptionally rough occupations—sailors and miners alike—often harbored an unexpectedly timid, fearful, and anxious side to their psyches that ordinary people could scarcely imagine. Just as sailors clung to bizarre superstitions about the sea or regarded its mysteries with disproportionate awe, miners too spread strange beliefs—that whistling underground inevitably provoked the mountain god’s wrath and brought cave-in disasters, or that the spirits of those who died in the pits lingered eternally at the site to curse future generations.
And as tools to soothe the miners’ persistent fears, whenever the pit became tainted by blood, sacred ropes would be hung there as purification markers—strange as these practices were, they had already become generalized customs regardless of their factual basis.

In the branch tunnels of Takiguchi Mine, the sacred ropes had been bleakly hung that day. And yet, before the fireproof door that should have been purified by those sacred ropes, fresh blood had ironically been spilled not once but twice. The miners—both men and women—in the branch tunnels, bathed in the dim electric light covered with wire mesh, kept a wary distance from the two corpses laid out with ominous intent before the closed fireproof door of the coal face, strangely hushed unlike their earlier commotion.

Engineer Koi’s corpse had been thrown down beside Engineer Maruyama’s straw mat-covered body, bent into the shape of the katakana ク. While stretching up to inspect the gas ventilation efficiency, he appeared to have been shoved from behind; the footstool lay overturned, and beside it sprawled an even larger coal block than in Engineer Maruyama’s case, smeared with blood. After he had fallen face down, someone must have mercilessly slammed that massive coal block onto him with crushing force. From the back of his head down to his neck, a massive wound had been jaggedly mangled, and his left ear had been crushed to the point of being nearly formless. The murder had been committed during the interval between when the section chief left the engineer alone at the fire pit and withdrew to the plaza office, and when the supervisor—who had gone to call Engineer Kikuchi at Tateyama Mine—finished his lunch and set out to resume his interrupted inspection rounds. Just as with Engineer Maruyama’s case, the culprit must have seized a moment when no coal carts were passing through the area to approach stealthily through the darkness.

The section chief turned as pale as paper while glancing around and irritably scattered the miners.

Engineer Koi’s murder had been committed using the same type of weapon as Engineer Maruyama’s killing.
Moreover, these parallels did not end there.
Like Engineer Maruyama before him, Engineer Koi too had harbored that single reason which might have led to his slaughter.
Wasn’t it none other than Engineer Koi himself—acting under Engineer Maruyama and the supervisor’s orders during the fire pit’s sealing—who had directly gripped a trowel in his own hands and smeared clay onto the iron door while executing Minekichi’s live burial?
The culprit was unquestionably one and the same—a pitiless avenger who had taken up Minekichi’s seething crucible of resentment following his entombment.

However, there, the section chief collided with a darkness of thought as impenetrable as an iron door.

Initially, when confronting the engineer’s murder, the section chief had quickly grasped the truth and arrested all those who could have become Minekichi’s avengers, launching a sweeping investigation—but during the course of interrogating these four suspects, Engineer Koi—who shared the same culpability as the engineer—had been murdered.
Moreover, the four suspects had indeed been confined in the office throughout the time of the engineer’s murder and had not stepped outside even once.
Then did the culprit lie among others outside those four?
But in this day and age, among these dull-witted miners, there couldn’t possibly exist such a theatrical madman who would inherit another’s grudge and systematically kill off company men one after another.

The section chief, who had until now dismissively brushed aside this matter, found himself utterly panicked and adrift like a kite with its string cut when he unexpectedly collided with an insurmountable obstacle.

However, there in the section chief’s groping in the dark, a glimmer of light was soon cast.
But this light—an inexplicable phosphorescent glow—instead plunged the section chief into the depths of ashen terror.

At Takiguchi Mine, they had established the practice of conducting the mine’s uniquely crude postmortem examinations on casualties in the infirmary at any time.
This was partly because the tunnel’s electric lights—though installed at intervals—were dim and caked with coal dust, and partly because the tunnels had been designed only to accommodate coal cart traffic, leaving them cramped and prone to obstructions that might impede coal output even slightly.

When notified that the medical staff had completed preparations and descended to the infirmary, the section chief decided to temporarily move the two corpses there. He spread straw mats over an arriving coal cart and loaded the bodies onto it.
And it was just as he himself was about to board the second cart together with the supervisor and constable.

A young miner came running out from the depths of the branch tunnel, carrying his own safety lamp and another extinguished one.
The miner stiffened upon seeing the section chief and said.

“At the water station, I found a safety lamp.”

“What? Found a safety lamp?”

The section chief turned around with a stern face.

In the coal mines, safety lamps were a lifeline miners could never part with.
They served not merely to illuminate the dark ground beneath their feet—the fluctuations of their flames made them invaluable tools for detecting explosive gas.
However, as previously noted, these lamps could prove extremely dangerous if mishandled. For this reason, the mine administration had assigned each lamp a dedicated user number and required inspection at the pithead checkpoint during every entry.
When one of these safety lamps was found abandoned with its owner unidentified, the section chief's face stiffened instantly.

“What number?”

“Ha-121.”

“Ha-121?”

The supervisor tilted his head.
The section chief jumped down from the coal cart and jerked his chin at the cart-pusher.

“Go to the watchpost and find out immediately which miner belongs to Ha-121.”

“In such a chaotic situation,” the supervisor leaned forward and said.
“It’s because of slack fools like this that we’re in such a mess,” he said to the miner.

“Where exactly did you find it?”

“Right next to the water station, lying there as if someone had forgotten it.”

“Water station”—though they called it that, it was nothing more than groundwater from a natural spring collected in a stone cistern. It was located in the dead-end tunnel of this branch section—the terminus where storage niches and a small clearing had been hollowed out. A crude latrine stood in that open space. When thirst gripped them, the miners would trudge there unbidden to drink.

“Left it behind?” The Supervisor barked impatiently. “Good—when we identify that man, he’ll be punished.”

The Section Chief scanned the cart-pushers milling about to confirm each still carried their safety lamp. None had abandoned their light in that lightless realm—forgetting was unthinkable here. This could only mean deliberate abandonment—a miner who either needed no illumination or found its presence obstructive—but as they weighed this puzzle, the woman cart-pusher came sprinting back without her coal cart, her face bloodless.

“Ha-121 is… the deceased Minekichi’s—”

“What?”

“Yes, that’s Minekichi-san’s safety lamp, I’m told.”

“What did you say? Minekichi’s safety lamp…”

The section chief’s face twisted into a grotesque expression in an instant.

“Wait a minute.”
“Minekichi’s safety lamp…?”

He had never imagined Minekichi’s safety lamp would surface.
There was no way left to punish Minekichi now.
No—rather than the impossibility of punishment, why would Minekichi’s safety lamp, which should have been with him when he died working underground, surface here and now?

The section chief—suddenly making a disgusted face—seized the safety lamp and addressed Supervisor Asakawa, whose demeanor had similarly altered, in a quavering voice.

“In any case, let’s take him into custody. Furthermore, let’s carefully consider one more thing. I’ve completely lost track of what’s going on here.”

IV

Engineer Kikuchi of the Tateyama Mine was not yet forty, in the prime of his career—a prodigy from Tokyo University’s Engineering Department who nonetheless detested growing pallid while chained to a desk, insisting he’d rather spend his free time tracking bear footprints with a rifle. With a sunburnt, ruddy face and a laugh that heaved his formidable shoulders, he had a voice that threatened to send blueprints flying off the desk when he chuckled.

Now, when Engineer Kikuchi arrived at Takiguchi Mine upon receiving the report, the petition officer had already left for the district police to request reinforcements, and the section chief who had discovered Minekichi’s safety lamp had abandoned both the autopsy and gas inspection to shut himself in the office, cradling his aching head with an uneasy expression.

However, when the section chief saw Engineer Kikuchi’s face, he regained some vigor.
He immediately began explaining the state of the fire pit, but as he continued speaking, his account unknowingly veered off course until the fire incident transformed into a murder case.
Engineer Kikuchi had also come expecting to deal with a simple fire incident, but as he listened to the section chief’s account, he gradually found himself drawn into that very narrative.
The section chief narrated every detail—starting from Engineer Maruyama’s murder and the four suspects, moving on to the foreman’s killing and the inexplicable reappearance of Minekichi’s safety lamp—and then, without explicitly naming it, piled into the engineer’s ears the glaring contradiction he had ultimately encountered and the uncanny suspicion welling up vividly from that contradiction, all while maintaining a guarded tone.

“This’s gotten as interesting as a bear hunt, hasn’t it?”

Engineer Kikuchi laughed dismissively after hearing the section chief’s account, though his inward struggle with comprehension showed through; he abruptly fell silent and sank into troubled thought.

“Honestly, being suddenly hit with such a bizarre murder case—it’s thrown me clean out of my depth.”

Eventually, the engineer broke the silence.

“But Section Chief, you’re being rather mean. Why don’t you bluntly state what you’re thinking? What suspicions are you confronting right now? Of course I understand them. And I fully realize how childish and foolish those suspicions are—no, rather, it’s sheer nonsense that defies all logic, something too absurd to voice seriously. But despite that, you lack the courage to outright dismiss that suspicion, don’t you? Please don’t take offense, Section Chief... Now then, there’s one method here to eradicate that headache of yours. It’s simple enough—let’s open up the fire pit and investigate.” “That’s right,” the section chief replied. “We can’t know exactly how much heat was generated during ignition, but it’s absolutely impossible for human bones to have been completely incinerated.”

“That’s right,” the section chief said. “The fire was contained quickly, after all. But gas is coming out.”

“But you’re ventilating it, aren’t you? If that’s the case, there shouldn’t be gas lingering that long, and besides, we have gas masks. Ah—but before that, Section Chief—”

The engineer, appearing to have gained some new insight there, suddenly lit up his eyes, looked around, and spoke.

“What happened to Mr. Asakawa?”

“Mr. Asakawa…?”

As the section chief turned around, the clerk standing beside him interjected.

“He was summoned by phone from the head office in Sapporo, but...”

However, Supervisor Asakawa returned before long.
The engineer finished his brief greetings and preliminaries, then immediately changed his tone and began.

“The truth is, Mr. Asakawa—this may sound odd—but at least three people must have participated in sealing that miner in. And you were one of them, weren’t you?”

The supervisor’s face drained of color.
The engineer continued quietly, his gaze sliding sideways.

“This murder case still hasn’t come to an end.”
“It seems it’s your turn now.”
“Ah, but—” The engineer lifted his face and began urgently.
“There’s no need to worry.”
“Listen—Mr. Maruyama and Mr. Furui were killed with coal blocks, but that serves as proof that the culprit has no weapon.”
“But you can now obtain a weapon.”
“Depending on the situation, you may even be able to capture the culprit.”
“Exactly.”
“Far from it.”
“Since you’re the one being targeted by the culprit, in this situation, you alone hold the most advantageous position to apprehend them.”
“The culprit hiding from us will surely reveal themselves to you.”

“I see,” the section chief said. “As one would expect from the bear-hunting expert—you do come up with clever ideas.”

However, Engineer Kikuchi continued seriously.

“So I’d like to make one proposal here to both of you. We’ll have Mr. Asakawa take a weapon and go alone to the crime scene vicinity. Of course, we’ll handle the rear guard afterward. As long as he’s armed, I believe there’s absolutely no cause for concern. What do you think? This approach should be quick and effective.”

The section chief immediately agreed.

Supervisor Asakawa briefly considered this, then stood up.
Then, retrieving a dagger purchased during the peak of the strike era from somewhere, he thrust its hilt against the floor with a thud and—

“Then I’ll entrust the rear guard to you.”

After saying that, he departed in an intensely tragic tone.

The Section Chief and Engineer Kikuchi waited a short while, then followed after the supervisor.
However, when they passed through the horizontal tunnel and came before the branch tunnel with the ignition pit, the engineer stopped and said to the section chief:

“If we prohibit entry and exit to these branch tunnels for one hour, how much would coal output be delayed?”

“What do you mean, stop the branch tunnels?”

The section chief widened eyes.

“That’s right.”

“This is no joke! Stopping work…”
“Stopping work…”

“But what if the culprit comes fleeing this way while we’re passing each other?” The engineer said. “How about it? If it’s just these branch tunnels, wouldn’t the delay be around thirty tons? Section Chief. If that’s all the sacrifice required, please go ahead and stop it. This is an emergency situation.”

“It seems you prefer hunting over bookkeeping.”

The section chief forced a bitter smile, and then Engineer Kikuchi immediately pulled the large fireproof door at the branch tunnel entrance, explained the situation to the panicking miners and foremen in the horizontal tunnel, rushed into the branch tunnel with the section chief, closed the fireproof door from outside, and had the foreman secure it with a bolt.
The line of coal carts that had coincidentally arrived at the left branch tunnel immediately encountered this abnormal closure and, still reeling from Minekichi’s recent entombment, began panicking in frenzy.
But when the people saw the section chief and engineer sealed in just like themselves, they quickly realized this wasn’t a malicious confinement but a temporary closure due to some circumstance, and the commotion that had begun to arise gradually subsided.

However, as they explained the situation to the cart-pushers they encountered along the way, the Section Chief and Engineer Kikuchi proceeded deeper into the branch tunnels—only to finally collide with an utterly unforeseen incident near the entrance to Minekichi’s sealed mining chamber.

Supervisor Asakawa, who had become the decoy, possessed physical strength surpassing most others, and moreover, since he carried a weapon, he should have been on high alert.
Furthermore, his opponent was hiding without even carrying a weapon.
Thus, there should have been no danger; yet despite this, by the time the section chief and engineer reached their destination, the supervisor already lay completely lifeless on the tunnel floor.

A flat coal block—larger than before and roughly the size of a stepping stone—lay pressing down on the corpse that had fallen supine in a spread-eagle position, nearly covering its entire upper body.
The coal block showed no signs of being transported from elsewhere. Fresh fractures marred the irregular surface of the adjacent coal wall, as though a cave-in had knocked the mass loose, while coal chunks of varying sizes lay scattered across the tunnel floor around the body like morbid offerings.
Upon Supervisor Asakawa’s beaten and near-death form, this final weapon had been slammed down by the murderer’s merciless hand.

The section chief involuntarily picked up the supervisor’s dagger and, while scanning their surroundings, removed the coal block from atop the corpse with the engineer’s help.
The corpse’s neck and chest had been crushed into a grotesque tangle, too horrifying to behold twice.

Having arrived mere moments too late, they’d lost even the chance to glimpse the murderer who stole away their precious decoy.
Though unforeseen, this failure weighed unbearably heavy.
Yet even as self-reproach assailed them, they found themselves compelled by the incident’s hatefully lucid implication.
The revenge plot had reached its completion.
What manner of man could execute such grand designs without wielding a single weapon?
Was the killer merely another miner in these branch tunnels—or—? The section chief’s gaze shifted toward the ignition pit’s iron door.
He stepped closer.
Pressed his palm against cold metal.
To his shock, all residual heat had vanished.
Engineer Kikuchi inspected the ventilation pipes.
The gas concentration had already thinned to near-safe levels.
Clicking their tongues in unison, they began scraping dried clay from the iron door’s seams.

Once the clay had been completely scraped away, Engineer Kikuchi lifted the latch and wrenched the iron door open with all his strength.
An uncannily tepid wind flowed from the darkness.
Holding out their dim safety lamps before them, they stepped into the opened ignition pit—marking its floor with their first footprints.
As soon as they entered, while angling their safety lamps downward from that spot, they began searching for Minekichi’s bones.
But in an instant, both men found themselves struck by an indescribable terror that defied all words.

Minekichi’s bones were missing!

No matter how much they searched, they found nothing. Like old cotton soaked in ink, the charred coal walls on both sides had receded irregularly; the torii-shaped mine timbers that had once supported them now stood grotesquely burned and decayed. Tar-like gas liquids oozing from the coal walls pooled across the ground, emitting foul odors here and there. They walked and walked, yet there was no trace of Minekichi’s bones—not even a speck of white bone powder remained. The two men began rushing through the tunnel as if possessed. But even as they pressed onward—past rails twisted like molten candy, past scattered pickaxe remnants and coal cart wheels flung aside, through air still unnervingly warm at the fire’s heart—reaching the very end of that mining chamber revealed nothing. Only then, grasping the gravity before them, did they freeze where they stood.

The worst-case scenario finally arrived.
As mentioned earlier, the coal pit was akin to a well bored horizontally into the coal seam—a space where, beyond the iron door shut tight at its entrance, not even a hole existed for an ant to crawl out.
The corpse of Minekichi—which should have been sealed inside that pit and engulfed in flames—if not the body itself, there absolutely should have been no way for even his bones to vanish without a trace.
Yet, the impossible miracle had surged forth there.
The Section Chief froze involuntarily, now fully conscious that his own fleeting suspicion had at last borne terrifying fruit.—

It was precisely at this moment.

Suddenly, utterly suddenly, shattering the quiet air around them, from somewhere overhead—far off, or perhaps close by—as if shaking the adjacent coal wall,

……Groan……

……Groan……

An indescribably strange sound had reached them.

In an instant, the two of them held their breath and strained their ears.
But that sound—neither quite a groan nor a reverberation—ceased immediately, and afterward, the silence returned once more.

However, for those who had spent long years living in the coal mine, that sound should have been immediately recognizable.

It was a dreadful sound one might occasionally hear in an abandoned pit where coal extraction had been completely finished—during moments like collapsing coal pillars and retreating.
When coal pillars are removed, in cases where the walls have become loose, the roof subsides due to ground pressure.
Subsidence always occurs gradually and intermittently, but when the stout timbers begin to buckle and fissures form in the roof, that uncanny reverberation could be heard.
That sound—a precursor to collapse, so to speak—was what the miners called "mountain groaning" and feared.

The sound in this instance was unmistakably that very phenomenon.
The timbers in the ignition pit had burned away, and as the air pressure inside—which had abruptly expanded at the moment of ignition—gradually subsided, the walls inevitably loosened, bit by bit beginning to sink under the ceiling’s weight.

The section chief turned pale and directed his safety lamp toward the ceiling.
But there, something even more terrifying was lying in wait.

Overhead, the ceiling pressing down bore two or three massive black fissures—crocodile-like gashes that had split open at some unknown time—and from within these charred cracks reaching deep into its interior, water droplets fell with a hollow *plink… plink…*.
The water had seeped in.
When the section chief noticed the water droplets, he immediately reached out his hand, caught one droplet in his palm, and apprehensively brought it to his mouth.
But in that instant, he jolted and leaped up.

When considered, ceiling collapses, fires, groundwater—all were inherent to coal mines.
For the Takiguchi Mine, they had prepared the best possible defenses and resolve against such eventualities, knowing full well they might one day come to pass—and indeed, against such preparations, there should have been nothing to fear. But now, this single drop of water upon the section chief’s tongue was what would seal the fate of the entire Takiguchi mining complex.
That water—which no possible means could ever stem—was neither groundwater nor gas liquid.
It was utterly ordinary, mere saltwater.

“We’ve miscalculated!”

The Section Chief—who had been the first to voice the arrival of the sea—let out an involuntary shout in a trembling voice.

“This isn’t just murder.
The sea has finally come!”

However, in the face of such a grave situation, a strange change began to occur in Engineer Kikuchi’s attitude from around that time. It was a settling of thought that resembled being in a daze—as if he had begun dozing off while standing—yet carried a bold, eerily lucid clarity.

“When your opponent is the sea, there’s no winning.”

Eventually, the engineer declared coldly:

“Come now, give it up, Section Chief. Since we still have ample time, let’s calmly begin evacuation preparations. Though you did say earlier this was ‘no time for murder,’ didn’t you? Indeed, that may hold true. However”—his voice sharpened—“this saltwater and murder are by no means unrelated. Section Chief, pay close attention to that large fissure with its charred cracks reaching deep inside. Somehow... I believe the truth of this incident is finally dawning on me.”

Five

Now, a few minutes later, an abnormal tension began to swell through the black underground city, centered around the sealed branch tunnels.

After locking the heavy iron door to the abandoned pit on the brink of collapse, the Section Chief hurriedly rushed to the phone room and delivered the dire news of seawater intrusion to Tateyama Mine’s surface office and Sapporo headquarters.
Next, to prevent crush victims at the narrow vertical shaft exit, he began implementing the most orderly evacuation preparations.

Meanwhile, Engineer Kikuchi—baring the goddamn guts he’d honed bear hunting—exited the iron door of the problematic branch tunnel, locked it again, summoned the bosses of the horizontal tunnels, and had them rigorously secure the sealed entrance.
The brutal murderer was somewhere in those deep branch tunnels.
Until they caught that man, nobody could escape from there.
Once this watertight security cordon had been established, the engineer made his way to the square’s office.

In the square, miners from the branch tunnel closest to the vertical shaft began withdrawing with bewildered expressions at the sudden strike order, murmuring as they retreated. Having finished urgently instructing several branch tunnel bosses one after another, the Section Chief spotted the engineer, ran over, and said:

“Now then, it’s the left branch tunnel’s turn.”
“Let’s go.”

“Wait.”
The engineer cut him off.
“Before that, there are two or three matters I need to investigate.”

“What did you say?”

The Section Chief was surprised and said impatiently.

“Why are you bringing up such a carefree matter now of all times? Isn’t the culprit already confined within that branch tunnel? We’ve got to flush him out and open up that tunnel immediately!”

However, Engineer Kikuchi did not move.

Finally, the Section Chief proposed beginning the investigation first—on the condition that no miners would be let outside until the engineer arrived.

When the Section Chief vanished into the horizontal tunnel’s darkness, Engineer Kikuchi immediately summoned Oshina—who had been detained in a separate room—to the office.
Oshina, questioned once more, began repeating her account of the outbreak with considerably calmer composure, just as she had done earlier for the section chief.
However, once the woman’s testimony concluded, Engineer Kikuchi pressed her with a forceful follow-up question.

“Now I’ll ask one more crucial thing—when you fled the fire pit and the supervisors, engineers and workmen rushed to seal the fireproof door, Minekichi was unquestionably not present there at that time, correct?”

“Yes, that is correct without a doubt.”

Oshina raised swollen eyelids and answered clearly.

The engineer closed his eyes briefly as if organizing his thoughts, then immediately stood up and headed to the phone room.
After about ten minutes, he returned.
It was likely a long-distance call.
However, Engineer Kikuchi—now returned—displayed an eerie resolve across his high forehead as he took Oshina and entered the horizontal tunnel.

In front of the sealed branch tunnels, standing pale-faced alongside two or three bosses—for some reason still clutching his dirk—was the Section Chief. When he spotted the engineer, he stepped forward and broke the silence.

“Kikuchi.
This has become quite a problem.”

“What’s wrong?”

“Well, you see… It’s completely absurd.”
“Actually, there’s no culprit in this branch tunnel.”
“Of course we checked all tunnels—every coal face, square, even storage pits—but there’s no sign of him.”

Then Engineer Kikuchi, in a calm tone, said something unexpected.

“Who exactly did you enter the mine to search for?”

“Huh? Who on earth were you searching for?”
“It has to be the culprit, doesn’t it?” the Section Chief blurted out in fluster.

“But that’s precisely the issue. You keep saying ‘culprit this, culprit that,’ but exactly who are you referring to?”

“What do you mean?”

The Section Chief, growing increasingly flustered,

“It has to be Miner Minekichi, doesn’t it?”

“Minekichi?”

Engineer Kikuchi started to speak but then fell silent with a troubled expression. After a moment, he sat down on a nearby coal cart and began in a quiet, formal tone:

"In truth, even I hadn't yet determined who the culprit was when we first entered this branch tunnel together."
"Though we'd indeed confined the criminal within these tunnels, we had no concrete target—just endless abstractions about 'the culprit,' utterly clueless who to actually apprehend."
"But now I've grasped the specifics."

Engineer Kikuchi got off the coal cart, approached the Section Chief, and continued his explanation.

“The specifics I’ve grasped appear to be more accurate than those you’ve grasped—Section Chief.”
“It seems you’ve made a major misunderstanding regarding this entire case.”
“You are too fixated on several superficial facts of the case and a plausible form synthesized from those facts—ignoring all logic. A miner was sealed away, and those who participated in sealing him are being murdered one after another.”
“However, among the bereaved families of the suspected miners, there is no culprit.”
“And yet, in exchange, the safety lamp of the miner who was supposed to have died sealed inside was discovered at a location other than the fire pit—and upon inspecting the fire pit, not only was there no corpse of said miner, but not even a bone remained. From this combination of facts alone, you must have harbored an extremely plausible suspicion: that the sealed-off miner himself had somehow come back to life, escaped outside the mine, and begun taking revenge on the men who entombed him.”
“However, its plausibility stems not from logic but merely from an interpretation of the facts.”
“Even if that interpretation is rich in plausible implications, we cannot simply accept such an outlandish contradiction—that someone escaped from a mine shaft that was absolutely impossible to escape—just because of it.”

“So how did you arrive at that?”

The Section Chief snapped bitterly.
The engineer continued.

“Let me get straight to the point.”
“When I found no trace of even the miner’s bones in that fire pit, that’s when I began forming a new hypothesis—since there weren’t even bones left in the tunnel, Minekichi must have escaped outside somehow.”
“However, they didn’t need to search every nook and cranny—once they closed the fireproof door, the fire was extinguished shortly after. This made it function like a fire snuffer, proving there were absolutely no other escape routes in that tunnel besides the fireproof door.”
“Then Minekichi must have exited through the fireproof door.”
“However, the fireproof door’s latch was on the outside, and the clay packed into the gaps had dried as it was applied, showing no signs of having been opened.”
“In other words, this means that from the moment the fireproof door was closed until we opened it earlier, it had absolutely never been opened.”
“Then Minekichi—you see—must have escaped before the fireproof door was ever closed… Now, with this new perspective we’ve reached, let’s examine other facts—this poor woman here, at that time, rushed out of the fire pit while hearing the sound of a man’s footsteps behind her.”
And when she rushed out, let out a sigh of relief, and turned to look back, Supervisor Asakawa—having heard the explosion and rushed over—had already begun closing the fireproof door.
And he had closed it.
Next, engineers arrived, workers rushed over, and the sealing began… This is the crucial point.
“Let me clarify: since Minekichi must have exited before the fireproof door was closed, he would have come rushing out right after the woman—and thus exited before Supervisor Asakawa closed the door.”
“In other words, Minekichi had been in the empty space between the woman—who had rushed out, let out a sigh of relief, and turned back—and Supervisor Asakawa—who had begun closing the fireproof door…”

“Wait, wait—what you’re saying… It sort of makes sense but doesn’t.”

The Section Chief grimaced and snapped as if cutting him off.
The engineer continued undeterred.

“That’s only natural you don’t understand.”
“Even I only began piecing things together bit by bit after pressing through with logical deductions… Truthfully, something utterly nonsensical occurred there at that moment.”
“What you might call fate’s cruel joke.”

Having started to speak, Engineer Kikuchi turned toward Oshina, who was standing nearby.

“There’s one more thing I need to ask you…… You said that when you returned from the winding station pushing the coal cart, you entered your mining area from the branch tunnel, and there in the dark tunnel—where Minekichi always came out to meet you—you rushed to embrace him. But was that man truly Minekichi?”

Oshina, at the engineer’s unexpected words, instantly caught her breath and widened her eyes.

“You said Minekichi always embraces you in that darkness there, didn’t you?”
“The man who embraced you in that darkness at that time—was he unquestionably Minekichi?”

“……Yes……”

“Then let me ask one more thing—was Minekichi holding a safety lamp at that time?”

“He didn’t have one.”

“What about *your* safety lamp?”

“It was attached to the rear of the coal cart.”

“So the safety lamp’s light—blocked by the frame—illuminated only the ground at the rear of the coal cart, not the front… You said you abandoned the moving cart and rushed to Minekichi, but that means until the cart reached Minekichi’s position, the lamp’s light never illuminated his face. And when the coal cart passed Minekichi and the light attached to its rear finally struck him, his body would have appeared as a shadow with the light at his back.”
“How could you have seen that it was Minekichi?”

“...”

Oshina looked bewildered and lowered her gaze.
But her face was brimming with unconcealable anxiety.
The engineer turned back to face the Section Chief.

“By now, you must have largely grasped what I’m thinking—or rather, what I’ve been forced to conclude… In short, Minekichi was never inside the mine from the very beginning when the fire broke out.”

“Hold your tongue.”
The Section Chief interrupted.
“So you’re claiming the man this woman embraced in the dark wasn’t Minekichi?”

“That’s correct.
Since Minekichi was neither outside nor inside, it inevitably leads to that conclusion, does it not?”

“Then who in God’s name is that man?”

“Since he rushed out after the woman and wasn’t left inside the mine, that man had been behind her at that moment—the one standing before the fireproof door.”

The Section Chief fell silent, stunned by this unforeseen conclusion.
But he swiftly rallied his composure and—

“If we follow your line of reasoning, the entire incident becomes some bizarre, incomprehensible mess. For example, if Minekichi wasn’t at the scene when the fire broke out, where on earth had he gone?”

“Ah, there it is,” said the engineer, pausing for breath. “Now, let us examine another fact with this new perspective… That safety lamp at the water station—you interpreted it as something Minekichi left behind after escaping post-sealing because it would hinder his murders. However, I now interpret that safety lamp as indicating the whereabouts of Minekichi, who was not in the mine at the time of ignition. Minekichi had gone to the water station.”

“I see.”
“So that’s how it is.”
“Minekichi had absolutely nothing to do with the ignition.”
“In other words, he had absolutely no involvement in the sealing.”
“Then why would Minekichi—who wasn’t even sealed—keep killing people who bore no grudge related to the sealing?”

“It seems you’re still bound by that erroneous preconception.”

Engineer Kikuchi gave a wry smile, clasped his hands together, and paced about restlessly as he said:

“Up to this point in my deductions, I should not have touched upon the matter of the culprit’s identity at all. Now then, let us examine another fact there. Concerning these murders—though the three killings may appear at first glance to have been committed haphazardly—several intriguing connections can in fact be observed. First, regarding the murder weapon: all three victims were bludgeoned to death with coal blocks. The fact that they were killed with coal blocks may seem insignificant, but the reality is anything but. Section Chief. Are you aware of what murder weapon appears most frequently in statistical records of homicide cases among miners? It’s hammers and pickaxes. There truly is nothing as readily available and robust for miners as these. Moreover, just like safety lamps, miners always carry one each as an essential work tool. However, in this incident, the culprit has—quite unusually—used coal blocks against each and every victim. Taking this fact into account alongside the overall sinister methodology of the incident, I considered that these might be crimes committed impulsively by someone who couldn’t obtain a suitable weapon other than coal blocks—in other words, not a miner. Now, you likely interpreted the shared reason why the victims of this incident were killed in the same manner as stemming from the grudge of the sealed man. However, since there was in fact no such thing as a sealed man, that line of thinking naturally becomes flawed. Of course, the three victims—operating under the misunderstanding that Minekichi was sealed in—must have incurred a shared resentment from the bereaved families. However, since there’s no culprit among the bereaved families, this too isn’t an issue. Now, if we ask whether there was no other common reason for the victims being killed—no, there *is* one… I had noticed this some time ago: all the victims were uniformly killed precisely while inspecting fire suppression or gas ventilation to reopen the sealed fire zone as quickly as possible. To reframe this: they were interfering with work—specifically obstructing *your* will to reopen the sealed fire zone and promptly investigate the ignition’s cause. To put it more clearly, the culprit did not want you to see inside the fire pit until a certain period. That’s why he tried to delay the reopening of the fire pit as much as possible.”

“Stay thy tongue.”

Once again, the Section Chief interrupted.

“What on earth did that culprit not want me to see so badly? Earlier, when you and I investigated that fire pit together, was there not anything related to this murder case?”

“There most certainly was.”
“Section Chief.”
“Please pull yourself together.”
“We made a significant discovery in that fire pit, did we not?”
“The major discovery that Minekichi—who should have been sealed inside—wasn’t there… No—it’s not that.”
“An even greater discovery—those ceiling fissures and saltwater!”

When they heard these words, an unusual commotion began among the miners standing nearby.
“Seawater intrusion!”
Compared to this fact, the past murder cases meant nothing to the miners.
The engineer, eyes blazing like fire and imbued with fierce resolve, addressed the Section Chief while suppressing the crowd.

“Open the branch tunnels.
“And have all the coal carts brought out immediately.”

When several foremen pulled open the heavy iron door with trembling hands, a thunderous roar erupted from the miners inside the branch tunnels.
Sweat-drenched female cart-pushers emerged pushing coal carts, their wheat-colored bare torsos glistening under the lamplight. The engineer stepped forward and barked:

“Dump all the coal here and retreat!”
“Empty every cart as you go back.”

The women exchanged glances and came to a halt at the engineer’s bizarre command, but when they immediately saw the section chief silently nodding beside him, they complied with the engineer’s order without question.

The coal carts at Takiguchi Mine were all dump cars of a type where removing the tenon from the frame would cause the box to flip over with a clatter.
The cart-pushers, obeying the engineer’s orders, came out one after another and flipped over the boxes on the spot, dumping the loaded coal with a gritty clatter.
In an instant, a mountain of coal formed there.
But when the twelfth or thirteenth coal cart flipped over its box, something extraordinary occurred there.

From within the coal that had poured out with a gritty clatter from the large box, a naked man—blackened head to toe with coal dust—tumbled out, sprang to his feet, and in shock began wildly looking around.
The section chief shouted.

“Hey, Supervisor Asakawa!”

It was indeed Supervisor Asakawa—the man who should have been crushed to death by a coal block.
As he reflexively braced himself to lunge, Engineer Kikuchi immediately struck him with a brutal blunt strike from the dirk he had snatched from the Section Chief.

When Supervisor Asakawa collapsed, Engineer Kikuchi—taking the dumbfounded Section Chief and Oshina in tow—boarded a coal cart and entered the opened branch tunnel, paying no mind to the clamoring miners.
Shortly after arriving before the fire pit, the engineer jerked his chin at “Supervisor Asakawa’s corpse” left lying there and said to Oshina.

“Take a good look at this corpse.”
“For appearances, they’ve dressed him in the supervisor’s fundoshi, but you should recognize this body.”

At first, the woman stood frozen in fear of the corpse, but gradually she leaned toward it until her upper body bent forward. Fixing her scorching gaze on the face—now so violently contorted it was unrecognizable as anyone’s—she drew closer, crouched down, and suddenly let out a strange cry as she lifted the corpse’s body. Still holding it, she turned around and rasped—

“It’s... my Minekichi.”

VI

At that moment, throughout the entire Takiguchi Mine, the engineer’s revealed words sent a violent shock.
At first, miners streamed out from Shaft No. 1, leaving about half their number behind. Once the fact of seawater intrusion spread among those remaining miners, all order—everything—collapsed there.
The miners threw down their coal carts, abandoned their pickaxes, and surged toward the hoisting station and vertical shaft like a tidal wave.
In the plaza office, the telephone bell rang incessantly from somewhere, and the rescue team that had arrived from the surface office overseeing both the Takiguchi and Tateyama Pits were scuffling with the miners trying to flee in front of the plaza.

Even as he leaped onto the last coal cart and rushed toward the vertical shaft entrance, the Section Chief nevertheless asked the engineer in a tone that couldn't quite let go—

"In other words, the man who killed Engineer Maruyama, the workman, and Minekichi was Supervisor Asakawa, right?"

The engineer nodded silently.

"Then what was Minekichi—the one killed last—doing all that time until then?"

"Minekichi was killed first."

“The very first?”

“That’s correct.”
“He was likely butchered at that water station.”
“After temporarily dumping Minekichi’s corpse into a nearby storage pit, Supervisor Asakawa then lit that coal face ablaze.”

“What do you mean he lit it?”

The Section Chief reflexively asked again.

"That’s correct."
"If you thought that was just an accident, you’re gravely mistaken."
"He rolled Minekichi’s pickaxe onto the rails, grabbed the woman in the dark, and used the couple’s habit and her safety lamp to ignite the coal dust."
"That was an utterly underhanded method."
"By doing it that way, even when the supervisory bureau investigated later, the responsibility for ignition wouldn’t fall on him."

“But why did he set fire to that coal face?”

“That’s it,” the engineer said, his voice rising.

“As I mentioned earlier, it’s because there was something in that coal face that absolutely couldn’t be shown to anyone until a certain time.”
“So by making it a fire pit to keep people out, he then eliminated Engineer Maruyama and the foreman—who later tried to open that door for firedamp inspections—for the same purpose.”
“Then you would ask—‘Why were we alone able to open that door safely?’”
“It’s because by then, that certain period had already passed.”
“Moreover, when someone like me showed up and pointed out—just as everyone’s assumptions were falling perfectly into the supervisor’s plans—that if these murders were revenge against those who sealed the mine alive, then logically the supervisor himself should be next... he panicked. He dragged Minekichi’s corpse from the storage hole, staged it to look like his own murder, slipped unnoticed into a coal cart to breach the tight security cordon, and tried to flee this Takiguchi Mine—now worthless to him.”

“Wait a moment.”
The Section Chief cut in.

“Earlier you said what the supervisor tried to hide were those ceiling fissures and seawater infiltration. But this remains completely separate from the murder case—moreover, when they set fire to that coal face, hadn’t the ceiling shifted yet?”

“Don’t be absurd.”
“The seawater infiltration and this murder case are intimately connected.”
“And Section Chief—”
“While the ceiling movement was certainly accelerated by ignition, it had actually begun shifting even before the fire started.”
“The earth’s crust must have been weaker than anticipated.”
“Furthermore—Section Chief—”
“Didn’t I caution you about this earlier?”
“Try to remember.”
“Look—that fissure had been burned through to its core, hadn’t it?”
“Meaning it didn’t split after burning—it split first, then burned.”
“Exactly.”
“The supervisor had discovered those fissures and dripping saltwater before anyone else.”

“I see.”
"But why did the Supervisor—knowing about this danger so early—why did he try to hide it even from us?"
“And also—what do you mean by this ‘certain period’ you mentioned?”

“That is the motive behind this incident.”
“When the Supervisor first discovered the seawater infiltration, he reported it to a certain party.”
“By containing this terrifying truth until a specific time, he stood to gain considerable compensation.”
“As for that ‘certain period’—you know what I mean.”
“When I arrived here, there was a call from Sapporo to the Supervisor, wasn’t there?”
“That call.”
“It must have been that.”
“There’s no error in this reasoning.”
“To verify my suspicions, I took the risk of calling the Otaru Exchange earlier.”
“And guess what?”
“Nakatsuki Coal Mine shares began fluctuating sharply around 11 AM today.”
“Starting at eleven o’clock.”
“Section Chief.”
“The company executives knew Takiguchi Mine’s fate hours before we on-site did.”

The engineer said this and vaguely cast a hollow gaze—as if still pursuing some unsolved mystery—toward the office lights that had just come into view.

However, within less than ten minutes of that, an abrupt, grinding, eerie subterranean roar—one that rooted the people fleeing in panic at the vertical shaft entrance to the spot—shook through the entire Takiguchi Mine.

And before long, in the mine’s drainage ditches, massive muddy water—gushing forth from who knows where—began rising inch by inch, swiftly overflowing as it scorned the four scorching multi-stage turbine pumps…

(*Kaizō*
Shōwa 12, May Issue)