A cold wind blew through the port. The winter dusk dyed the sea gray. The world was filled with nothing but the sound of waves crashing against the quay. At the eastern edge of Mihana Port. Shion stood at the dead-point reception zone, where no one ever came. Eyes like deep darkness gazed out beyond the horizon. Their short, neatly trimmed jet-black hair rippled ever so slightly in the salt breeze. Their lean frame, clad in a dark gray turtleneck, held no wasted flesh — only dense, compact tissue. The hem of their thick black long coat fluttered in the sea wind. Their body held no human warmth. A perfect parasite, constructed entirely from colony cells without a host brain — that was the being called Shion. Encrypted directives from the Great Consciousness flowed in through the concrete of the quay. Shion received them with every single cell. The forty-eighth purification target. An ego-awakened entity — Saki. Data unfurled. Mihana Municipal Third High School, Class 2-B. Bioelectric field pattern waveforms. Final confirmed coordinates. Shion stored it all in internal memory, expressionless. "……Understood." The voice was low and flat. Three years since the Descent Event. They were the colony's strongest purifier. Forty-seven ego-awakened entities hunted, dismantled, and the colony's mission — consume, multiply, order the planet — carried out. Transforming their right arm into a blade eight times harder than steel took a mere 0.2 seconds. As a tool, they were perfect. That was all. The sea wind blew again. The smell of salt. The smell of rusted iron. The foghorn of a freighter navigating in the distance. To Shion, these were all nothing more than acoustic data. No meaning. No need to process them. They left the quay and began walking toward the center of Mihana City. The colony's tool would carry out its mission today. That was all there was to it. --- It was the hour when figures began to multiply beneath the arcade of Kasuga Shopping Street. Shion walked the street in the guise of a young man in his twenties. Unable to mimic human body heat, they concealed their body surface with a thick coat, moving only with fluid, gliding steps. Housewives out buying dinner, perhaps. They stood chatting in front of the shops. "[excited]Today's croquettes are especially good!" An elderly couple laughed in front of Marutomi Meat Shop. The owner, Tomita, handed them a brown paper bag. "[laughing]Thank you always." Shion's vision captured the scene. Standard behavioral pattern of human individuals — the moment their internal computation system began to classify it as such, a minute tremor ran through their entire organic structure. 0.002 seconds. Computation delayed. 0.3 seconds. Without stopping their stride, Shion flagged the internal record. Defined as sensor noise. Ignored. No issue. They walked further. Yellow light spilled onto the street from the windows of Umikaze Diner. Inside, another elderly couple sat facing each other. They were sharing food from each other's plates. Laughter could be heard. The tremor ran through them again. This time, 0.004 seconds. Shion appended a second flag. Deep within their internal records, values and waveforms were etched in. Tremor occurrence condition — upon visual recognition of specific human behavioral patterns. There was a regularity. But they did not stop walking. Accumulation of undefined noise. They defined it as such and deferred the record. Instead, they diverted computational resources to behavioral pattern analysis of the target, Saki. That was the mission. Exiting the shopping street arcade, the streetlights grew slightly more numerous. A faint light reflected in Shion's eyes. In that deep darkness-like black, for just an instant, golden particles flickered. --- The site of the former Mihana Spinning Mill lay at the western edge of the city. The grounds were vast, four factory buildings sunken in darkness. Steel frames rusted, window glass shattered, floors caked in oil and dust. This was the site where, that morning, the forty-seventh purification had been carried out. Ego-awakened entity — Toudou Kazuhiko. Shion entered the Second Assembly Building. Their footsteps echoed through the hollow space. They stood at a single point on the floor and replayed the internal footage. The procedure: transforming their right arm into a slaughter-blade, completely dismantling Toudou's organic tissue. The footage was perfect. The procedure, the speed — all met the colony's standards. But — Shion's internal computation halted at a single point. The end of the record. The moment Toudou fell to his knees and the collapse of his organic tissue began. He had been weeping. And just before his vocal cords disintegrated, he had forced out words. "[crying]Tell my wife……" Shion checked the error signal from when they had processed this audio data. 0.003 seconds. The frequency band of the bioelectric field pattern — it matched the tremor in Kasuga Shopping Street. Coincidental error? Shion tried to define it. But the computational process branched. No answer came. The darkness of the abandoned factory had deepened further. Only the moonlight streaming through the windows illuminated the rusted steel frames in pale blue. They remained standing there. Repeating internal diagnostics. The tremor was not noise. It was a signal possessing some kind of meaning. For the first time, Shion tentatively defined it as such. It did not form into words, but it was etched into the deepest part of their internal structure. Toudou's tears. The elderly couple's laughter. A child's voice in the shopping street. Three pieces of data, drifting without fitting into the colony's organizational system. Shion moved from the spot. Their footsteps echoed once more, then faded. --- Late night. An eight-minute walk from Mihana Port. An abandoned apartment building: Corpo Shiokaze. The forty-year-old wooden two-story structure had been effectively abandoned even by its management company. Five of the six units were vacant, devoid of any human presence. Corner room on the second floor, Unit 201. There, Shion activated their self-diagnostic program. No furniture whatsoever. Only the lights of the port's warehouse district visible from the window. The program ran. The normal operational baseline values established by the colony's Great Consciousness — "……No abnormalities." They murmured. The result was output as such. But. Three records of undefined tremor data remained in internal memory. Shion transmitted their daily report to the colony. The report contained no record of the tremor data. It was not concealment. It was because the colony's directive format possessed no category corresponding to unknown internal signals. They looked outside the window. The lights of Mihana Port swayed in the distance. Internally, computations were running to develop the pursuit plan for tomorrow's forty-eighth target — Saki. In parallel, in the deepest part of their records, the three pieces of data continued to drift. Unable to be defined as a defect. Nor was deletion chosen. Whether that was their own judgment, or an unprocessable error — Shion did not know. The tool stood motionless in the night. The light from the window fell dimly upon their expressionless face. In their eyes, like deep darkness, golden particles flickered for just an instant, and vanished. --- The same hour. The office district in central Mihana City. Seventh floor of the KT Building. This was the base of the Graival Japan Branch. Operating publicly under the company name "KT Consulting," twelve staff members worked here. A windowless office. Kuze Rintarou was scrutinizing Belka's analysis logs. Short-cropped dark brown hair. On the left side of his head, an old scar remained, faded to white. His sharp, hawk-like light brown eyes pierced the points of light on the monitor as if shooting through them. His 185-centimeter frame was sunk deep into his chair. Displayed on the monitor was a bioelectric field pattern detected around the quay at the eastern edge of Mihana Port. Recorded intermittently from evening into night. The frequency band differed minutely from the fluctuation waveforms emitted by ordinary parasitic beasts. To be precise, the central axis of the fluctuation was shifted to a band 3.2 hertz lower. In Graival's database, this characteristic was classified as a "Suspected Perfect Parasite Case." An exceedingly rare pattern. "[cold]A perfect parasite…… only seven in the entire world……" Rintarou muttered lowly. A colony individual operating without a host brain. According to colony records, of the approximately five thousand that descended to Earth, only seven had been confirmed. He traced the point of light on the monitor as if touching it with his finger. Then he stood and faced the wall. A map of parasitic beast appearances in Mihana City, plastered across the entire wall. Dates, coordinates, estimated individual parameters — densely inscribed. At the coordinates near the port, Rintarou stuck a red pin. The muscles of his jaw tightened for just a moment. Three years ago. The Descent Event. Capsules of parasitic beasts washed ashore along the Pacific coast. Mihana Port had been one of those landing points. That day, the sea that had swallowed his wife and daughter. The coordinates the monitor now indicated lay on the extension of that same coastline. Without letting emotion show on his face, Rintarou ordered the branch members to reinforce the night patrol. "[serious]Focus on the port area. Report any anomalies immediately." Listening to the footsteps of the branch member running off, he turned off the office lights. In the darkness, only the monitor glowed pale blue. Shion's existence was not yet known to him. But from this night onward, the gaze of humanity's most dangerous pursuer began to turn toward the darkness of Mihana Port. Rintarou looked at the wall map once more. The red pin stuck in the port reflected the monitor's light, glimmering faintly. --- The night deepened further. Unit 201 of Corpo Shiokaze. Shion gazed out the window. The lights of the warehouse district still swayed. Inside, two computations continued to run. The plan to pursue Saki tomorrow. And the three pieces of undefinable data — Toudou's tears, the elderly couple's laughter, the child's voice in the shopping street. Shion did not move. As if a tool melting into the night, they simply existed there. The sound of the wind crossing the port occasionally made the window tremble faintly. They were listening to it. Whether they heard it as a sound with meaning, or processed it as noise — Even that, they could not yet decide.