1. 灰雪

The white figure did not move. Sakuma stared until his eyes watered from the cold, but the shape remained perfectly still, a vertical smudge against the dark trunks. He took a step forward—and the figure vanished, not retreating into the trees but dissolving, as if it had been made of mist all along. He blinked, rubbed his eyes, and saw only falling snow and the silent pines. The wind picked up, carrying a low moan that might have been the branches or might have been something else.

He walked back to the general store with deliberate slowness, forcing his breath to steady. Oba was already awake, feeding kindling into the stove. She did not look up when he entered, but her hand paused over the firebox for a fraction of a second. He said nothing about the platform or the figure. Instead, he asked for hot water and a bowl of rice. She served him without a word, and he ate while watching the window, where the snow had thickened into a white curtain that hid the entire ridge.

By mid-morning, the storm had eased to a flurry. Sakuma put on his boots and walked toward the clinic, which stood at the eastern end of the village—a single-story wooden building with a corrugated iron roof and a sign reading "Tanaka Clinic" in faded blue letters. A narrow porch held a rack of boots, none of them modern hiking gear, all of them worn rubber wellies. He knocked, and Tanaka's voice called out from inside, cheerful and welcoming.

The examination room was small but immaculate: a stainless steel table, a cabinet of bandages and syringes, a sink with a drip that fell with metronomic regularity. Tanaka sat at a wooden desk, writing in a ledger with a fountain pen. He looked up and smiled the same warm smile. "Sakuma-san! Come in, come in. I was just reviewing the winter medication stock. The elderly need their blood pressure pills, you know."

Sakuma returned the smile and sat on the patient chair. "I wanted to ask about the old mining shafts you mentioned. I'm mapping all potential hazards, and I'd like to know their exact locations."

Tanaka set down his pen. "There are three main shafts, all sealed in the 1970s after the sulfur operation closed. The entrances are covered with concrete slabs, but the ground around them is unstable. I can draw you a rough map." He pulled out a sheet of paper and began sketching, his hand steady, his lines precise. Sakuma watched his fingers—the calluses on the index and middle fingers, the slight yellowing of the nails, the absence of any tremor. These were not the hands of a man who had spent decades only writing prescriptions.

While Tanaka drew, Sakuma let his eyes wander. The cabinet to the left had glass doors, revealing rows of pill bottles and ampoules. The cabinet to the right was metal, with a solid lock, no window. A thin gap at the bottom showed a sliver of dark floor. Sakuma leaned slightly to the side, trying to see under the door, and caught a glimpse of something orange—a piece of synthetic fabric, crumpled against the baseboard. He recognized the color instantly: the same fluorescent orange trim used on the Metropolitan Police's standard-issue winter parka, the model Miki had been issued two years ago.

Sakuma kept his face neutral. "That's a detailed map," he said, as Tanaka slid the paper across the desk. "I appreciate it."

"Anytime. We don't get many visitors, so it's a pleasure to be useful." Tanaka capped his pen and placed it precisely beside the ledger. "By the way, I heard you visited the shrine platform yesterday. That old stone is not safe—the frost has cracked it in several places. I advise you to stay on the main trails."

"Thank you for the warning." Sakuma folded the map and tucked it into his coat. As he stood, he made a show of stumbling, catching himself on the metal cabinet, and in that motion, he pressed his thumb against the lock. It was a standard pin-tumbler, not a heavy security lock. He could pick it with a paperclip and a bit of patience, but not now.

He left the clinic and walked back through the village. The snow had stopped, and the sun broke through the clouds for the first time in days, casting long blue shadows across the roofs. He passed a group of three elderly men who were clearing the path in front of the communal hall. They nodded curtly but did not speak. One of them wore a cap with a faded emblem—a mining lamp crossed with a pickaxe. That emblem dated back to the Showa era, when the sulfur mine had been the village's only industry. Sakuma filed the detail away.

He spent the afternoon circling the village perimeter, noting the locations of the three shafts on Tanaka's map. All were sealed, but the concrete slabs were cracked, and in one case, a corner had crumbled to reveal a dark opening barely wide enough for a man to squeeze through. He did not enter; he simply marked the coordinates on his own notebook and took a photograph from a distance.

As dusk fell, he returned to the general store. Oba was in the kitchen, and the smell of miso soup and grilled fish wafted through the house. She served him dinner on a low table in the main room, and for the first time, she sat down across from him without her knitting needles. She poured herself a small cup of sake, then poured one for him.

"You went to the clinic," she said. It was not a question.

"Yes. Dr. Tanaka was helpful."

Oba took a sip of sake, and her eyes, which had been sharp and assessing, grew distant. "Tanaka-sensei came to this village thirty-two years ago, fresh from medical school. He said he wanted to serve a community that had no doctor. We were grateful. We still are." She paused, swirling the cup. "But he never left. Not for a single vacation, not for a conference. He stays here, winter and summer, year after year. Do you know any young doctor who does that?"

"Maybe he loves the mountain life."

"Maybe." Oba drained her cup and poured another. Her voice dropped, and Sakuma leaned forward to catch the words. "My husband was one of the elders, back in the old days. Before he died, he told me things. He said the village had a rule, older than the shrine, older than the mine. A rule about blood and shame. He said that when a family could not purify its own stain, the whole village had to carry the weight. And the only way to lift it was to send the stain away—forever."

Sakuma felt the hairs on his arms rise. "Send it where?"

"The mountain. The fog. The place where the air burns your lungs." Oba's voice cracked. "There was a boy. My husband never said his name, but I knew. Everyone knew. He was the son of the family that ran the mine office. His father was a brute, a drinker, a man who had no mercy for his own children. The boy did something—something terrible, but also something that many thought was justified. But the village did not see it that way. They saw a son who raised his hand against his father, and they said that was the worst kind of defilement."

Sakuma kept his voice soft. "What happened to the boy?"

Oba looked at him, and for a moment, her eyes were clear and terrified. "They gave him two choices. The stone—the old prayer stone—they tied him to it, and the head elder said, 'You can be buried here, where your blood will feed the roots of our shame, or you can walk the fog road and never return.' He chose the fog. But the fog road leads to the sulfur vents. A child cannot survive that." She set down her cup with a clatter. "I was not there. I was a young bride, and they told me to stay inside. But I heard the boy's sister scream. I heard her scream for three days. And no one went to comfort her. No one."

Sakuma wanted to ask more—the sister's name, the boy's name, the date—but Oba stood abruptly, knocking over her cup. The sake spread across the table like a bloodstain. "I have said too much. Go to sleep. Tomorrow, leave this place. Take the morning track and do not look back."

She retreated to her room and slid the door shut with a finality that left no room for further questions. Sakuma sat alone in the dim light, listening to the old house creak and settle. He pulled out his notebook and wrote: "Boy—mine family—father abusive—sister—screamed three days—choice between burial and fog road—Oba's husband was elder—Tanaka arrived 32 years ago, same age as boy would be."

He slept poorly, dreaming again of the boy, but this time the boy had a face—a narrow face with high cheekbones and a scar above the left eyebrow. The same scar that Shiori had. A genetic marker, or a coincidence? He woke at dawn, his mind already churning.

He dressed and stepped outside to find the village wrapped in a thick, motionless frost. The sky was a pale lavender, the kind of colour that promised a clear but bitter day. He walked toward the shrine, intending to examine the platform again with fresh light. But before he reached it, he heard a commotion—voices raised, a woman weeping. He changed course and followed the sound to the communal well, where a cluster of villagers had gathered.

At the center of the circle lay Oba's body, splayed at the bottom of the well shaft. She had fallen in during the night, they said. The well was only four meters deep, with a narrow rim, but she had been old and unsteady on her feet. The village's only doctor, Tanaka, was already there, kneeling by the edge, his face grave. He looked up as Sakuma approached.

"A tragic accident," Tanaka said, his voice soft and sorrowful. "She must have come to draw water before dawn. The rim was iced over. A slip, a fall, and she struck her head on the stone wall."

Sakuma looked down. Oba's body lay crumpled at the bottom, her right arm twisted beneath her, her head resting against a mossy rock. There was a dark stain on the rock—blood, still wet. But the well's surface was not icy; he could see the water trembling below her, and the rim was dry, swept clean by someone's broom. He looked at the faces of the villagers—some shocked, some sad, but none of them surprised. They had seen death before. They had seen it often enough to know the proper expression, and they wore it like a borrowed coat.

Tanaka stood and placed a hand on Sakuma's shoulder. "I know you were lodging with her. This must be a shock. I will handle the formalities. The prefectural police will be notified, but the snow may delay their arrival for a day or two."

Sakuma nodded, forcing his face into a mask of grief. But inside, his mind raced. Oba had spoken the truth last night—the truth about the boy, about the rule, about the sister. And this morning, she was dead. A slip, he thought. A fall. But he remembered the black dust on the floor of her shop, the way she had swept it toward the door as if she were erasing a line. He remembered her trembling hands, her warning to leave.

He turned away from the well and walked back toward the general store, but he did not enter. Instead, he circled to the back, where a narrow alley led to the kitchen door. He tried the handle—unlocked. He stepped inside and looked at the counter where Oba had kept her knitting. The sock with no heel was gone. The stack of newspapers from three weeks ago was gone. But on the floor, near the stove, he spotted a single object: a broken sewing needle, bent into a curve, as if someone had used it to pick a lock.

Sakuma picked it up and slipped it into his pocket. He did not know whose lock had been picked, or when, but he knew that Oba had not died by accident. She had been silenced, and the one who silenced her had been thorough enough to remove every trace of their conversation—except the needle, which had rolled under the stove, too small to notice.

He stepped back outside and looked toward the clinic. The chimney was smoking, the windows dark. Tanaka was inside, perhaps washing his hands, perhaps writing a death certificate. Sakuma thought of the orange fabric under the metal cabinet, the callused fingers, the gentle smile, and the story of a boy who walked into poison fog and never came back.

But what if he did come back? What if he survived, crawled out of the sulfur vents with his lungs scarred and his mind reforged into something harder than stone? And what if he returned, not as a victim, but as the keeper of the village's oldest secret—the one who decided who deserved to stay and who deserved to vanish?

Sakuma pulled out his notebook and wrote: "Oba killed—silence enforced—Tanaka's arrival date exactly matches boy's age—orange fabric in clinic likely Miki's—needle suggests Oba may have tried to access something (the clinic? the shrine?) before her death." He underlined the last sentence twice.

Then he looked up at the ridge, where the fog had begun to roll down from the sulfur vents, white and gray and silent. Somewhere in that fog, a boy had walked to his death. And somewhere in this village, a man who had once been that boy was still walking, still waiting, still watching.

Sakuma did not go back to his lodging. He walked instead to the shrine, knelt beside the platform, and pressed his bare hand against the stone. The cold bit into his palm, but he held it there, feeling the grooves, the scratches, the weight of decades. He whispered a question to the mountain: "What do you want from me?"

The mountain did not answer. But the fog thickened, creeping down from the ridge, swallowing the trees one by one. And in the distance, he heard a sound that might have been the wind—or might have been a man's voice, humming a lullaby.