In the margin of the notebook, three words lay in a row. "Mitearai River." "Old Weir." "1963." 柏木信也 sat in a second-floor guest room of the inn "Mitearai Lodge," facing the notebook he had left open since the previous night. Beyond the window, the Mitearai River received the morning light and flowed in hushed silence, while the blue ridge of Souryoudai across the way still lay submerged in thin mist. It was the heavy, quiet whiteness peculiar to winter mornings. A slip of paper pressed into his hand without a word in the corridor of the Amagasaki family headquarters building—he recalled once more this morning the face of the employee who had given it to him. An expressionless profile. A single moment in passing. Anyone rooted in this town would have understood better than most the magnitude of risk contained in that act. Yet they had given it to him anyway. 柏木信也 took up a pencil and began cross-referencing the three words on the slip with his existing chronological notes. 1963. The year a young woman from a branch of the Amagasaki family had vanished without trace, appearing in only a few lines in the local newspaper of the time, processed as an "elopement." Tracing backward from the cyclical recruitment announcements and record disappearances beginning in 1993, the starting point converged upon this era. Not at the end of thirty years of accumulated practice, but at the first layer—the oldest darkness still unrecorded, compressed within these three words. From annotation to skeleton. 柏木信也 quietly confirmed that moment of elevation. He put on his jacket and closed the notebook. In the morning air where the smell of rust from the window frame mingled with the faint dampness of the river, he drew a single breath before leaving the room. ＊ When 柏木信也 arrived at the Local History Room of Hinomori Municipal Library—a reinforced concrete two-story building seven minutes' walk south of Hinomori Station, adjacent to the Citizens' Park along the Mitearai River—小暮真帆 was already seated before the microfilm reader. Her long straight hair, tinged with pale purple-black, swayed quietly in the winter morning light streaming through the window. Her bright, clear green eyes gazed intently at the reader's screen. On the desk lay a notebook covered in adhesive notes and several pages of pencil-written notes. A small mole on her left wrist flickered into view as she turned over the memos. When 柏木信也 opened the door to the reading room, 真帆 looked up. "Good morning," A polite but brief greeting. Her voice, as always, held no excess words. 柏木信也 hung his coat on the back of a chair and surveyed the desk. Last night's phone call had contained only a single request: "Please check the local newspapers from the Mukuroki Prefecture area around 1962 to 1964." Yet this morning's desk held systematically organized notes and an already-running reader. "How long were you working?" 真帆 kept her eyes on the screen. "Activities outside business hours leave no record," she answered in a tone perfectly professional for a librarian. 柏木信也 simply said he understood. It was an exchange that functioned as quiet understanding between two people who did not call gratitude by its name. ＊ The August 1963 page that 真帆 had threaded into the reader spread across the screen. Old typeface floated in the grainy gray peculiar to microfilm. 柏木信也 leaned closer to the screen. In a corner of the local news section—just below a Chamber of Commerce announcement, at the boundary between a column and an advertisement—there was a small article of fewer than five lines. A young woman from a branch of the Amagasaki family reported missing. The prefectural police announced the possibility of running away from home. That was all. There was no follow-up. 柏木信也's pencil recorded the article's date in his notebook. Then 真帆 slightly adjusted the reader's focus. The screen shifted sideways. Another article appeared on the same page of the local news section. Rokugatsu-do Construction—a comprehensive construction company headquartered in Hinomori City, Mukuroki Prefecture, still a mid-sized enterprise not long after its founding at this time—had received a contract from the prefecture for large-scale riverbank reinforcement work in the middle reaches of the Mitearai River. Two articles lay side by side on the same page. 真帆's finger slid a handwritten memo toward 柏木信也. Two dates were written there. The date of the missing person report. The scheduled start date of the construction work. The difference was eleven days. The two exchanged no words. They confirmed without speaking that their thoughts had reached the same conclusion—both understood precisely the danger that verbalization would transform an assertion without evidence into a definitive claim. Outside the window, the surface of the Mitearai River rippled, and its reflected light traced white patterns across the ceiling of the reading room. After a time, 真帆 spoke. "There is an additional point," Her voice carried a faint warmth of intensity. "The 1963 riverbank reinforcement work was a large-scale project that far exceeded the scale of Rokugatsu-do Construction at that time. The period required for the prefecture to allocate such a budget, when measured against the records of the Mukuroki Prefectural Assembly at the time, was clearly too short. It was not a pace that followed the normal deliberation process," 柏木信也 wrote in his notebook. 真帆's supplement quietly exerted pressure upon the blank space between the two articles. The outline of the hypothesis became slightly more distinct. "I want to confirm the site," When 柏木信也 spoke, 真帆 answered with barely a pause. "I will accompany you," 柏木信也 hesitated for only a beat. The judgment that 真帆's knowledge of local history was indispensable to a site outside the record, and the resistance to bringing her to a place where he did not know what lay ahead, momentarily balanced against each other. But judgment prevailed over resistance. 柏木信也 nodded. ＊ The ruins of the old weir lay about six kilometers south of Hinomori City, beyond a farm road where the pavement ended. They parked the light vehicle at the edge of the farm road and proceeded on foot. Dead grass accumulated beneath their feet, making a dry sound with each step. The low afternoon light of December slanted in, and the groves along the tributary of the Mitearai River cast long shadows on the ground. Cold air touched their cheeks. 真帆 walked half a step behind 柏木信也, clutching a small notebook to her chest. Stone masonry came into view. The remnants of the old weir. Since the completion of a dam upstream in the 1980s, the water level in this area had changed, and the weir had been left abandoned, stripped of function. Stones covered in moss and grass lay stacked in irregular patterns. Sixty years of time had fallen upon it in equal measure. 柏木信也 walked slowly around the stone masonry. He was not searching for anything. He was trying to confirm the air of this place with his body. 真帆 placed her hand on one of the stones. Her green eyes looked toward the water's surface. "The old course of the Mitearai River should have run through here. The riverbank reinforcement work changed the course, and it became the route it follows now," Her voice was quiet. "In other words, before 1963, this place was close to the main current of the river," 柏木信也 received those words. He looked at the stone masonry. The work that had changed the river's flow. The riverbank reinforcement work that had begun eleven days after the disappearance. There was no evidence. It was inference. But the structure of the inference was far too coherent. For the first time, 柏木信也 verbalized the hypothesis to 真帆. "The current four disappearances and the incident from sixty years ago may correspond as the starting point and present form of an identical structural practice," When spoken aloud, its weight changed. 真帆 did not deny it. Standing on the dead grass, she slowly traced the cover of her notebook with her finger. Both understood precisely what it meant that this could not be denied. On the return journey, driving back along the farm road, 真帆 spoke. "The site of the branch family residence is now a materials yard for Rokugatsu-do Construction," A quiet remark from the passenger seat, her eyes on the winter-bare landscape beyond the window. Vacant land. 柏木信也 processed the implications of those words while gripping the steering wheel. The fact that the grounds where the branch family had once resided now served as a materials yard for Rokugatsu-do Construction—he deferred for a time the translation of that fact's meaning into words. ＊ They returned to "Mitearai Lodge" after evening had passed. Yoshie Doumoto, the proprietress—sixty-seven years old, her short white hair neatly arranged, a woman of always gentle voice—had come to announce dinner at an hour earlier than this late return. 柏木信也 placed his jacket in the room and looked from the window toward the direction of Souryoudai. The ridge line of the grove sinking into the color of night barely indicated the outline of the roof of the Amagasaki family main residence. The stone masonry of the old weir, the five lines of the microfilm, and the vacant land where the branch residence had stood were becoming a single line in his mind, yet not quite connecting. There was no evidence. Without evidence, only the pressure of hypothesis grew. That night, the fixed telephone rang. When he picked up the receiver, there was silence. There was a presence—he could sense that someone was on the other end of the line. But it ended in five seconds. 柏木信也 set down the receiver and wrote "22:14" in his notebook. ＊ The next morning. Before he could hear the sound of Proprietress Doumoto walking down the corridor to announce breakfast, 柏木信也 was already outside. A folded piece of paper was wedged in the windshield of his parked car. When he opened it, three lines of printed text appeared. Not handwritten. A character string output by a printer, bearing no emotional warmth. "Stop poking around." The meaning of its being printed rather than handwritten, 柏木信也 grasped in a single second. Not the anger of an individual. A warning issued as an organizational decision. Someone had judged, someone had approved, someone had carried it out. This single sheet existed within that chain. 柏木信也 tucked the paper into his notebook. In that moment, the sensation from three years ago returned. As bodily memory—as the coldness of his fingertips, as the contraction in his chest. The sensation of that night when he had deleted the article he had been writing in the social affairs section of the Toyo Hochi newspaper, folder and all. His fingers resting on the keyboard had remained still for a long time that night. And when they moved, they had entered the delete command. He had obeyed fear. That was all. Now the same question had come again. Would he retreat here? 柏木信也 stood in the parking lot without moving for a time. The cold morning air pricked his earlobes. In the distance, the sound of the Mitearai River's flow reached him. There was no certainty. He was not acting from a sense of justice. Only—the barely-held sensation that if he obeyed fear once more, nothing would remain of him, that alone lay beneath his feet. Then the inn's front door opened. "Oh, Kashiwagi-san. You're already outside," The proprietress's voice was gentle, dissolving into the morning air in rounded tones. She looked at 柏木信也's face and tilted her head slightly. "Your complexion doesn't look well. Did something happen last night?" "No, something on the windshield—" As 柏木信也 began to speak, the proprietress glanced at the parking lot and then nodded softly. "Frost, dear. Frost. It falls quite often this time of year. Please have your meal while it's still warm," With those words, in her kindness, she turned back as though nothing had occurred. 柏木信也 watche