Pathway to Japanese Literature

I

The Akimori estate—a considerably spacious south-facing mansion situated immediately west of Yoshida Yūtarō's apartment in N Town—stood as a markedly antiquated structure; its gray tiled roofs speckled with map lichen here and there were so thoroughly enveloped by a dense mixed grove of lush sawtooth oaks and Japanese red oaks that they remained nearly invisible from any window of the apartment building. Furthermore, this old mansion's perimeter was conspicuously encircled by what appeared to be a full ten feet of sturdy stone wall—newly reconstructed just this winter—that rose with particular prominence in this specific area.

The front of the mansion faced a quiet six-ken road running east-west before the apartment, separated by an elongated vacant lot of approximately three hundred tsubo that stretched laterally. To the south of this weed-choked lot lay a cliff over a dozen jō high, its sheer face resembling white stone cleanly severed.

Yoshida Yūtarō had felt a mild curiosity toward this Akimori family's old mansion ever since moving here.
This curiosity wasn't limited to the mansion's exterior alone, but centered primarily on the Akimori family residing within.
Though nearly half a year had passed since his arrival at the apartment, beyond occasionally glimpsing a young woman who appeared to be a maid at the back entrance on the stone wall's western edge facing the rear street, he'd never once seen anyone resembling a family member nor witnessed the aged tall wooden gate being opened.
In short, the Akimori family struck him as gloomy recluses who seemed abandoned on this quiet hillside as if forgotten by society.
To be precise, occasional rumors suggested their household comprised an elderly master past sixty along with two unmarried sons - these three joined by a middle-aged steward and his housekeeper wife plus one or two maids inhabiting the spacious mansion.
Yet even those sharing such accounts admitted never having actually seen either the patriarch or his sons.

However, suddenly using the Akimori estate as its stage, an utterly incomprehensible and bizarre incident arose.
And through a mere trifle of circumstance, Yūtarō-kun found himself thrust into the very maelstrom of it all.

It was one sweltering midsummer Sunday.
At 2:30 in the afternoon—having finished writing a letter to his hometown for some minor business—Yūtarō-kun recalled that at this precise hour, as usual, the postman would come for the second collection at the apartment’s front postbox. He left his apartment.
Habits proved formidable indeed; just as Yūtarō-kun had expected, the conscientious elderly postman was already hunched before the postbox, clattering his key against the collection slot.
Yūtarō-kun approached him, exchanged brief greetings, and handed over his mail. Then—gazing at the postman’s sweat-drenched profile etched with deep wrinkles—he thought: Sweltering.—Let it be noted this Yamate neighborhood stood particularly hushed even ordinarily, with scant foot traffic; yet on this scorching day beneath a blazing white sun that poured its rays unabated, not so much as a stray kitten crossed the six-ken road out front despite midday’s height—the stillness lay thick as sprinkled water.
Within that silence, catastrophe erupted.

At first, Yūtarō-kun and the postman heard a low, sharp scream—inexpressibly chilling—coming from the direction of the Akimori estate's front gate to their west.
As one, they turned their gaze toward it.
Then, about thirty ken from where they stood by the postbox, right before the Akimori estate's front gate, two men in white yukata came tumbling into view—leaping over what seemed a large black mass—before fleeing shoulder-to-shoulder along the high stone wall in the opposite direction.
But in that same breath, their figures vanished behind the estate's long stone wall curving northward with the road—gone without trace. Though everything happened too suddenly at that distance to discern their features, this much was clear: both men shared identical builds and wore matching white yukata with black heko obi.
Yūtarō-kun felt lightheaded and stumbled against the nearby postbox.
When he jerked back from its scorching iron surface—now blistering under the sun—the elderly postman was already sprinting toward the estate's front gate.
Yūtarō gave immediate chase.
Yet when they reached the gate, no trace remained of those suspicious men.
The black mass resolved into a victim collapsed face-down—crawling posture frozen mid-motion—now barely breathing.
Unmistakably a middle-aged woman with unnaturally pale neck.
Something red had already begun spreading across the pavement.
The postman crouched frantically to lift her while shouting at Yūtarō-kun: “Chase them that way!”
He punctuated this with a sharp jerk of his chin.

The six-ken road curving northward in a gentle arc before the Akimori estate bent sharply northward from the western end of the estate's stone wall, following its contour.
Yutaro-kun frantically dashed to the right-curving corner and lunged forward to peer down the long road ahead.
The right side of the road was bordered by the Akimori estate's long stone wall.
The left side was bordered by an equally long and high brick wall marking the rear of a certain baron's estate.
A single straight road with likely no hiding places—
But the culprits weren't there!

Instead of the culprits, from the other side of the street came a single Western-clad man who appeared to be some company agent, carrying a black leather bag in his hand.
Yutaro-kun ran up and promptly asked.

“Did you not encounter two men wearing white yukata on this road just now?”

“…”
The man stood frozen in stunned silence for an instant, but unexpectedly, he immediately began shaking his head vigorously while—
“I didn’t see any such men.”
“...Did something happen?”

"This is bad!" Yutaro-kun blurted out, visibly flustered, "Right now—there's been a murder at Mr. Akimori's gate..."

"What?!"
The man's face rapidly paled. "A murder?! Who's been killed?" he gasped out in fragments, breaking into a run alongside Yutaro-kun who had turned back.

"I am the steward of Akimori—Togawa Yaichi."

However, as soon as they rounded the stone wall's bend and glimpsed the Akimori estate's gate ahead, the two kept running without speaking. When they soon saw the woman—now slumped over with the postman lifting her up while pressing a handkerchief to the chest wound—the Western-clad man lunged forward.

“Ah! Someko!”

and then he began glancing around restlessly as if possessed—

"...Th-this... this is my wife..."

Having said that, he plopped down and stayed there.

From around the curved corner came the raucous commotion of a madcap chindonya troupe, clinkety-clanking its way closer.

II

A few minutes later.

It was the N Town police box.

Rookie Officer Hachisuka stood dazedly in the scorching heat, fighting against drowsiness as might be expected.

At that moment, a chindonya street performer rushed in breathlessly—his back bearing a sign reading "Café Lupin," his belly cradling bells and drums—and breathlessly blurted out how he had just passed by the Akimori estate's front when a horrific murder occurred; how three men stood panicked by the corpse; and how he had come straightaway to report it.
Murder!
Officer Hachisuka jolted upright as if struck by electricity.
He checked his watch.
It was ten minutes to three.
After hastily reporting to the local police station by telephone, he immediately dashed off with the chindonya in tow.

At the scene, besides the aforementioned three, maids from the Akimori household and several other onlookers had gathered.
When Officer Hachisuka appeared, Yoshida Yūtarō—who had until then been restraining the onlookers—stepped forward and presented a bloodstained dagger that he had reportedly picked up from the roadside along the wall, approximately five ken west of where the victim had collapsed.

Officer Hachisuka promptly moved to conduct preliminary interviews with the witnesses.

“So... what you’re saying is... Mr. Yoshida chased after those two men in yukata from this direction.
“Mr. Togawa comes from the opposite direction.”
“Hmm, so it’s a pincer attack.”
“And yet it’s a single straight road! …But there’s no culprit? …Then…”

Officer Hachisuka began measuring the road's length, furrowing his brows and biting his lower lip.
But when his gaze reached the small back gate—cut into the western end of the Akimori estate's stone wall near the curved corner—it fixed itself motionless.
Yet when he soon turned back, he smiled while looking between the two witnesses as if weighing them equally.
Naturally, both Yutaro-kun and Steward Togawa immediately grasped Officer Hachisuka's implication and nodded deeply.

“This is troubling,” said Steward Togawa, his face darkening.
“There truly exists no other exit besides that one.”

Thereupon, Officer Hachisuka eagerly dashed off, opened the back entrance door, and entered the mansion. But before long, when he emerged from that doorway, he declared triumphantly.

“Hmm.”
“Bullseye.”
“There are footprints!”

Just at that moment, a solemn squad of police officers arrived, led by the Chief Inspector.
Officer Hachisuka proudly reported the details of his preliminary investigation, appending the evidentiary items provided by Mr. Yoshida.
And soon, the witnesses were subjected to a second round of questioning.
The victim was the Akimori family's housekeeper and Someko, wife of steward Togawa Yaichi.
As there were two eyewitnesses to the crime—Mr. Yoshida and the postman—and since the cause of death had been conclusively determined to be a straightforward stabbing that killed her instantly, the woman’s corpse was soon removed.
And as a result of the testimonies from Mr. Yoshida, the postman, and Steward Togawa, the Chief Inspector proceeded to investigate the aforementioned footprints discovered by Officer Hachisuka.

First, they opened the back gate and entered the mansion grounds. About five ken ahead—nine meters—straight ahead was the kitchen entrance. To the left lay the interior of the curved stone wall. To the right, through the plantings of the spacious front garden, the main house stood visible beyond. The ground showed uniform dampness from having apparently been watered against the day's heat. Between the back gate and kitchen, footprints from work shoes and felt zori sandals—likely those of tradesmen and household servants—lay overlapping in layers. The footprints Officer Hachisuka had discovered turned right immediately from this back gate, continuing in scattered traces across the ground that led from the front garden's plantings toward the main house. They were garden geta tracks. There were an extraordinary number of them.

The investigation revealed that the garden geta tracks roughly formed four distinct lines.
This indicated two people had made round trips through this area wearing garden geta.
Had they entered from outside and exited back out?
Or exited from inside and returned back in?
However, such doubts were resolved by the distinctive garden geta footprints whose front and back could be clearly distinguished.
Soon after, two pairs of garden geta that perfectly matched the ground traces were discovered at the shoe-removal area by the main house's edge.

The Akimori family was suspicious.

The police officers buzzed with sudden urgency.
The Chief Inspector left Officer Hachisuka to monitor the footprints, relocated his headquarters to the main house's veranda edge, and commenced investigating the Akimori family members under the joint observation of Yutaro-kun, the postman, and Steward Togawa.

Akimori Tatsuzō, the elderly master, reported being unable to attend questioning due to an immobilizing illness.
As testimonies concerning this illness had been provided by the steward and maids, the Chief Inspector summoned the two sons.
Yet when Yoshida Yūtarō and the postman glimpsed the men who appeared, their faces drained of color.

The two sons were perfect duplicates in both physique and facial features, both wearing similar white mosquito-patterned yukata and identical black brocaded-silk heko obi sashes.
Their names were Hiroshi and Minoru, both aged twenty-eight—clearly twins.

For an instant, an awkward silence swelled among those present.
But immediately, the postman shouted in a trembling voice as if he could no longer endure it.
"It's... it's these people! There's no mistake!"

Thereupon, the Chief Inspector commenced an even more rigorous interrogation.
However, the Akimori twins—who claimed to have been napping under the wisteria trellis in the back garden until mere moments prior—responded that they hadn't the faintest idea what was happening and categorically denied any connection to the crime.
They even asserted they'd never ventured into the front garden or anywhere of the sort.

Thereupon, the two maids were summoned again. However, the older maid called Natsu—who had been attending to the elderly master almost exclusively in the detached rear residence—answered that she knew nothing about the main house matters. The younger maid called Kimi answered that while it was true the young masters had been napping under the wisteria trellis, she herself had actually dozed off for about an hour afterward. Furthermore, she added that shortly before the incident occurred, a phone call had come from somewhere, prompting housekeeper Someko to go out after entrusting her with watching the place—but being half-asleep in a daze, she had overslept and could only offer apologies.

Thus, even through the maids' testimonies, the twins' alibi for not being at the scene remained extremely incomplete; and worst of all, whenever the questioning touched upon the matter of the victim Togawa Someko, the twins would inexplicably stare vacantly or timidly hesitate in their speech.
This clearly damaged the investigators' perceptions.
Thereupon, the Chief Inspector dispatched one of his subordinates to the Metropolitan Police Department’s Forensics Division to make the final determination by comparing the twins’ fingerprints with those left on the handle of the confiscated murder weapon.

III

Now, on the other hand, rookie Officer Hachisuka—who had been entrusted with guarding the footprints—felt considerable satisfaction inwardly, thinking he had already made a great achievement in his first murder case since joining the force. With that, he found his job rather delightful and, clasping his hands behind his back while nodding emphatically, wandered back and forth along the line of footprints.

Studying them like this, even footprints turned out to be quite fascinating.
For example——Officer Hachisuka crouched near the small back gate, looking at a single pink advertising flyer trampled into the garden geta tracks as he pondered.
For example, since this advertising flyer was trampled into the garden geta tracks facing the small gate, it must have been stepped on when the wearer of the garden geta emerged from the garden plantings and slipped out through this small gate.
——Hmm.
A café advertisement.
Lupin... Lupin?
Hmm, I’ve heard that name before…

Suddenly realizing something, Officer Hachisuka stood up. While intense bewilderment clouded his forehead, he remained motionless for some time; but when he saw the maid Kimi—who had finished her questioning and emerged into the kitchen—he approached and called out to her.

“You.”
“I need to ask you something.”
“Where do newspapers and advertising flyers get delivered to this house?”

“Huh, newspapers?” She straightened up while wiping her hands on her apron. “The newspapers are delivered through that small gate all the way to the kitchen.”
“The mail too.”
“But for advertising flyers and such, they just open that small gate a bit and toss them in through there.”

“I see. Thank you.”

Officer Hachisuka nodded deeply.
Yet his complexion rapidly paled, an even more intense look of bewilderment rising to his forehead as all his previous vigor vanished somewhere. While biting his lower lip firmly, while vigorously tapping the area around his temples with trembling fingertips, he froze like a statue.

This is strange... In other words, from here, the advertising flyers are tossed in... Then, on their way to kill the woman, the killer steps on this flyer that was thrown in... Does that make sense?
But does that really make sense?
...No good... No good.
This makes absolutely no logical sense!
Officer Hachisuka began to agonize intensely.

Just then, the Chief Inspector and his team—having completed their interrogation—came marching out triumphantly escorting the twins Hiroshi and Minoru.
Officer Hachisuka suddenly began to panic.
And in a flustered tone, he said to the Chief Inspector.

“Wait! There’s something I need to clarify.”

“What’s that?” The Chief Inspector leaned forward. “A doubt? Don’t be ridiculous! It’s perfectly clear! There was a call from Forensics. The fingerprints on the murder weapon’s handle match Akimori Hiroshi’s exactly!”

Officer Hachisuka withdrew without resistance.

Before long, the group withdrew and left.
And so the Akimori twins were taken into custody at the police station as nearly definitive culprits, and the case began to show a degree of resolution.

However, the one who couldn't settle was Officer Hachisuka.

When his shift ended at dusk and he was off duty, he came to the Akimori residence still brooding over the matter. And at the usual spot by the back entrance, after having the maid from earlier accompany him as a witness, he crouched down before the advertising flyer trampled into the garden geta tracks and began reconsidering everything once more.

——Café Lupin advertising flyer.
This must certainly have been one of those flyers scattered by that chindonya troupe.
So—had this advertising flyer been thrown in first?
Or had the two perpetrators passed through here first?
But the immediate fact remained—the flyer had been thrown in first, then afterward the two perpetrators emerged, unknowingly trampling it with their garden geta—that was the only possible interpretation.
That’s right.
There could be no mistake about this fact.
Then... then that would mean—the chindonya troupe had passed through this gate before the perpetrators exited through it—before the tragedy occurred... Did that hold up?
Did that make sense?
...No good... No good.
The chindonya troupe must have passed through after the incident occurred... This defied all logic!

Officer Hachisuka stood up impatiently.

——That was it.
In any case，he would try contacting the chindonya troupe once.
And whether that chindonya troupe had possibly passed through here even before the crime?
It should be impossible by all logic—but just to eliminate every doubt—he had to verify it.

Thereupon, Officer Hachisuka left the Akimori residence and began walking eastward along the stone wall.

——If it were indeed confirmed that the chindonya troupe had thrown in the flyers after the crime as he suspected…… then those culprits' footprints…… That's it.
A horrifying trap.
A dreadful scheme...

Officer Hachisuka continued walking, deep in thought.
However, here and now, Officer Hachisuka unexpectedly stumbled upon yet another baffling problem.

Just as he reached the crime scene before the main gate of the Akimori residence, Officer Hachisuka—startled by something—suddenly came to a halt. And while staring fixedly ahead, he began tilting his head repeatedly. But eventually clicking his tongue in annoyance, he began striding forward with a noticeably disheveled gait. And when he arrived in front of the apartment, he briskly rushed into the entrance and headed toward the reception desk—

“Please summon Mr. Yoshida Yūtarō.”

he said.

Mr. Yoshida Yūtarō, whose nerves had been worn ragged from attending the interrogation, had unintentionally begun dozing off in his room—but upon being startled awake, he hurriedly rushed down the stairs. And when he saw Officer Hachisuka’s face,

“Did something else happen?”

“No, it’s nothing serious, but there’s something I need to ask you.”
“Excuse me, but could you come with me for a moment?”

With that, he started walking.

"What on earth is this?"

Yutaro followed behind Officer Hachisuka and asked urgently. But Officer Hachisuka continued walking without uttering a word, and when he eventually came before the front gate of the Akimori residence and stopped at that spot on the pavement from earlier, he suddenly turned around and said—

“Right now, the place where we’re standing is the crime scene—in other words, where the victim fell, correct?”

Yutaro was startled by this absurdly obvious question.
And as he trembled and nodded vigorously, Officer Hachisuka—this time fixing him with a probing gaze—continued staring at Yutaro while,

“I believe you as a serious witness, but you did say that at that time, you were standing right next to the postbox in front of the apartment and saw the victim lying here, correct?”

“That’s right.”
Yutaro pressed urgently, “If you think I’m lying, then ask the postman too.”

“Hmm, I see.”
“Then from here, looking that way—the postbox standing at the pavement’s edge should naturally be visible... What do you think?”
“Can you see the postbox?...”

Yutaro turned pale.
Where Yutaro’s gaze reached—there was not even a trace of the postbox to be seen!
The streetlamp that should have been a few ken ahead of the postbox was dimly casting its pale light into the dusk—but beyond that, swallowed by the shadow of the tall, sharply curving stone wall, the postbox’s silhouette was nowhere to be seen!
Officer Hachisuka placed his hand on Yutaro’s shoulder and said in a trembling voice.

“You! What on earth is the meaning of this?!”

IV

Having become completely agitated and spent nearly the entire night sleeplessly thinking, Mr. Yoshida Yūtarō was nevertheless shaken awake early the next morning by Officer Hachisuka. He changed into his clothes in extreme ill humor and left his room.

“I’d like to ask for a bit of your help,” the rookie officer began in a suddenly friendly tone while descending the stairs. “Last night, I couldn’t sleep a wink either. After that, I spent the entire night searching for those drunken chindonya performers. As a result—though this is still confidential—I made a significant discovery... In other words, the two perpetrators trampled on the advertising flyers from the chindonya troupe that passed through there some time after the crime—using those garden geta. Therefore—well—you. Those garden geta footprints were not left by the true culprits during the crime—they’re a terrifying scheme deliberately created afterward to frame those twins. The true culprit’s identity remains unknown, but in any case, those Akimori twins are definitely not the perpetrators!”

While exiting the apartment, paying no heed to the astonished Yutaro, he suddenly grew gloomy,

“However, at the station, my opinions aren’t being considered at all… There are witnesses, evidence has been gathered, and worst of all, subsequent interrogations revealed that those twins had an unsavory relationship with the murdered housekeeper.”
“Well, that was quite a shock.”
“Whether she had that relationship for payment, or whether it formed from her own morbid curiosity-driven passion—in any case, they’ve made that unsavory relationship into a prime criminal motive.”
“And then there’s last night’s incident, you see.”
“This is utterly rotten… But I don’t want to hit a dead end here.”

When they arrived at the Akimori estate's gatefront, Officer Hachisuka took out a large measuring tape from his pocket and had Yutaro assist him in beginning the most precise measurements yet of last night's miraculous phenomenon involving the stone wall.
However much they tried, from the postbox, the spot where the victim had fallen remained hidden behind the gently curving stone wall.
Similarly, from where the victim had fallen, the postbox was nowhere to be seen.
Officer Hachisuka finally threw down the measuring tape and said.

“Mr. Yoshida.”
“I’ll ask just once more—and this’ll be the last time—so please consider this helping me out and give me an honest answer. Will you?”
“You were definitely standing right by this postbox with that postman and saw the crime scene with your own eyes—correct?”

Yutaro couldn’t help but flare up at Officer Hachisuka’s relentlessly persistent questioning, but stifling his irritation, he gave the same answer as the night before.

“Hmm, so it was just as I thought... No, I shouldn’t have doubted you.”
Officer Hachisuka said while putting away the measuring tape.
“Then this long stone wall would have to be jutting out at least three feet further into the road than it was back then… Utterly absurd… No—thank you,” he said with a nod to Yutaro. “But in any case, this could potentially become a matter of witness accountability, so please bear that in mind.”

With those words, Officer Hachisuka left, looking somewhat agitated.

This had become troublesome.
Yutaro sighed as he thought—Could I have been mistaken?
No—there was absolutely no way he could be wrong.
Yet even so, it remained utterly strange.
Moreover, Officer Hachisuka had declared the Akimori twins weren't the culprits!
Then who in blazes was the criminal?
Who served as mastermind and who as accomplice?
No—could another pair of twins exist?
Or perhaps...

Yutaro had now moved beyond mere interest in the inexplicable and was beginning to feel genuinely uneasy.
And at the same time，Officer Hachisuka’s parting shot struck him right in the gut.
—A matter of witness liability?
Tch，what an outrageous nuisance.
Yutaro continued to be tormented by anxiety.
No matter how much he thought about it，the solution remained elusive.
And in the end，having realized he couldn’t make head or tail of it on his own，Yutaro began searching for a reliable senior who could lend him a hand.

Ah, Aoyama Kyōsuke!

Yutaro suddenly recalled the strange man who had been coming to give lectures now and then at the school he attended.

That's right.
From what I hear, that person had been involved in several criminal cases before.
If I explain the circumstances, he would surely agree to help me...

So Yutaro promptly went to visit Aoyama Kyōsuke as soon as school let out.

“Wasn’t that case already resolved?”

Having said that, Kyōsuke curtly offered Yutaro a chair.
However, when Yutaro began meticulously recounting the facts he had witnessed as a witness—Officer Hachisuka’s newly discovered theory negating the culprits’ guilt, the strange occurrences before the stone wall, and his own difficult position—Aoyama Kyōsuke gradually leaned forward, interjecting a few questions mid-narrative and closing his eyes in contemplation until finally he stood up,

“I’ve got a clear picture now.”
“I’ll help you out.”
“But as that Hachisuka fellow says, the culprits aren’t the Akimori twins. …You’re asking who they are?”
“As for that, kindly wait until tomorrow evening.”

Five

The following day felt interminably long for Yutaro-kun—needless to say.
The excruciatingly frustrating movement of the clock's hands became more than Yutaro-kun could endure, and once night had fallen and he had finished his dinner, he hurriedly rushed out.

Aoyama Kyōsuke was sitting in an armchair, having waited impatiently for Yutaro-kun.
"I met that Officer Hachisuka today—he seems quite a competent man."
Kyōsuke said.
"With this case, that man’s promotion is certain!"

“So you’ve already identified the real culprit?”

“Of course it is.”
“Since hearing your account last night, I had already grasped the general picture.”
“There’s nothing to be surprised about.”
“Look here.”
“The situation is really quite simple, isn’t it?”
“In other words—on that single path, you and the postman gave chase to the two culprits from this direction.”
“The steward comes from the other side.”
“But there’s no culprit.”
“So you peer into Akimori family’s back entrance—the sole escape route.”
“Then there are the culprit’s footprints.”
“But here’s the thing.”
“If those footprints were made long after the crime was committed—what would that mean?…”

“……That would mean the culprit didn’t enter through the back entrance at that time…”

“That’s right. And outside the wall, there were three men—you all. …Do you understand?”

“It’s like I understand… but I don’t…”

“How exasperating… The culprit was outside that wall… Meaning the culprit was among you three!”

—This can’t be serious!
Yutaro-kun nearly cried out.
But Kyōsuke cut through—

“Among you three—from when the billposter passed by and threw flyers into the back entrance after the crime, up until Officer Hachisuka rushed over upon that billposter’s report and discovered the footprints—there was a man who entered the estate through that back entrance during that time, wasn’t there? …That guy’s the culprit.”

“So, Steward Togawa is the culprit?”

“That’s right. By the way, about how many minutes was Togawa inside the estate?”

“About five minutes? That’s about it. But the steward, while leaving his briefcase, was going to inform someone of the emergency…”

“That briefcase—what I investigated today with Officer Hachisuka was this: Inside it was a complete set of white yukata and black casual sash! In other words—Togawa summoned his wife by telephone while everyone was napping, stabbed her before you witnesses with the murder weapon pre-marked with the twins’ fingerprints, then beyond the curved corner outside your sightline removed the yukata he’d worn over his Western clothes and stuffed it into the briefcase. After leaving that in the estate grounds, he hastily executed his garden clog trick and roused the maids—that’s his entire scheme. Nothing more to it. From the Akimori twins’ scandalous relationship with the murdered woman—the crime of passion motive that the police attributed to the twins—I simply reversed it and thus quite naturally made the woman’s husband, Togawa Yaichi, bear that same motive instead.”

“Then what about the other accomplice…?”

“An accomplice?
“There was never any accomplice to begin with.”

“Wait.
“Are you dismissing my eyesight?
“I clearly saw two culprits with these own eyes—”

“Now, your agitation is understandable.
“This supposed accomplice you speak of is deeply tied to that stone wall’s miraculous phenomenon.
“The true culprit who discovered this phenomenon deliberately orchestrated the crime before you witnesses—particularly before someone like the postman who’d inevitably pass by at a fixed time.
“Ah, what’s wrong?
“You.
“Is your head aching?
“No, it’s only natural.
“That stone wall’s miracle does hold truly baffling qualities.
“I’ve already formed a general hypothesis, but you’d scarcely believe it from a brief explanation.
“Give me two or three more days.
“At any rate, I must now go to the police station—”

Now, it was three days later that Aoyama Kyōsuke relieved Yūtarō-kun of the source of his headaches.

The day was oppressively hot, exactly like that day of tragedy, but Kyōsuke, Yūtarō-kun, and Officer Hachisuka walked along the road flanking the Akimori estate, pummeled by the scorching heat of 2:30 PM.
When they finally reached the familiar curved corner, Kyōsuke declared:

“We shall now commence the experiment.
“And it is sure to succeed.
“We will walk along this stone wall to the position where the victim fell before the main gate.
“Once we reach that spot, if the postbox—the one that should be invisible—comes into view before us, then the phenomenon will have been explained.
“Pay attention.
“Let us begin walking.”

Yoshida Yūtarō and Officer Hachisuka started walking as if possessed by foxes.
Five ken... ten ken... fifteen ken... Now only five ken remained to the Akimori estate's main gate, but even that soon... four ken... three ken... And then—ah!—the miracle finally manifested!

Though they were still nearly three ken away from where the victim had fallen, the red postbox that should have been thirty ken beyond the curve in front of the apartment began emerging from behind the stone wall with startling clarity—its vivid form materializing against all expectation.
As the three of them advanced, its form gradually became fully formed—and finally separated from the stone wall's shadow.
—What on earth—?
Overlapping with that postbox, another similar one began to come into view.
And by the time the three of them stood before the main gate, two red postboxes had abruptly lined up and were standing thirty ken away.
Yutaro-kun felt a light dizziness and involuntarily closed his eyes.

And abruptly, Kyōsuke said.

“Look! The postman’s twins are coming!”

Truly—when you looked—the grotesque postman’s twins wearing frosted-patterned clothing and carrying a large black briefcase were gradually approaching from beside the postbox!
But strangely enough, as the twins approached the three men, they began to gradually overlap from being twins into a single person.
And soon there stood the honest postman at that spot—eyes wide with shock for some reason—rooted in place as he stared fixedly in their direction.

“Ah, it’s a mirage!”
Suddenly, Yūtarō-kun shouted.

“Hmm—not quite on the mark, but not far off,”
Kyōsuke said.
“In other words, it’s a type of atmospheric refraction.
When differences in temperature cause localized changes in air density, light rays bend—allowing objects’ images to appear in unexpected abnormal directions.
What’s called a mirage.
This one—it’s a small-scale version of that phenomenon.”

……Today was particularly sweltering, just like the day of the tragedy.
And this new large south-facing stone wall—through the combined effects of reflected heat from the vacant lot opposite and its own length, height, and other detailed conditions—became intensely heated, creating localized variations in air density along its surface.
"So from our current position," he explained, "the light rays heading toward that postbox reflected and refracted through the air, bending tremendously until—abruptly—the 'stone wall's miracle' manifested."
Kyōsuke chuckled while gesturing at the postman with his chin. "...Heh heh... Look.
"The postman who ignored the prescribed distance and approached has ceased being twins—and surely you too must be standing there astonished at this wonder we've witnessed regarding our own bodies."
"...In any case, should just thirty more minutes pass with the stone wall's temperature dropping even slightly, or should any one of these complex conditions creating such a truly rare spectacle break down—then that postbox would vanish from sight... Well now... It seems your headache has finally cleared up, hasn't it?"

(From Shin Seinen, July 1935 Issue)