Kai woke to the taste of dust and the small relief that he could move without the city rearranging him again. The plateau's light had shifted; the sun—if that was what it was—had climbed another shallow arc and painted the plain the color of old coins. Around the scrap of shelter where they'd spent the night people moved like things trying to remember themselves: rubbing sleep from their faces, turning bundles for inspection, arguing about where to go next in voices that were too loud for no reason other than habit.
Kai sat up, flexed his fingers, and listened. The Sentinel at his back hummed; its eye tracked the plain with patient impatience. He tasted the morning like a problem he could solve with the right tools. The system in his pocket vibrated once and the voice—flat, precise—spoke as if reading from a ledger.
Citizen Registration available. Survivors may be designated as Citizens. Effects: allocative mana contribution +5% per Citizen, defensive matrix scaling. Requirements: consent from subject, owner confirmation.
Kai let the voice finish rather than interrupt. He had expected mechanisms—rules were a kind of mercy—but not this exact mercy. The idea that people could become literal, mechanical inputs to a structure felt distasteful in theory and exquisite in practice. He found he liked it.
He grinned, small and involuntary, the expression of someone who had just been handed a better set of numbers. "Oh. Wow," he said aloud, because some facts deserved spoken acknowledgement.
Miri, who had been rummaging through a torn bag and humming tunelessly to herself, glanced up. "What's the tally?" she asked. Her grin was messy and human; she had not yet learned any of Kai's social filters.
"It says you can register people," Kai answered. "Citizens. They give a portion of their mana output and growth to the structure. It strengthens the tower."
Miri's eyebrows disappeared for a beat. "So if I give you my luck, you'll make me a house?" she asked. "Because I can part with luck like old gum if the price is a roof."
He allowed a small smile. "Not luck. Output. Effort you can't spend while the tower farms it. You get protection. I get permanence."
An old man who had been sorting through a pocket watch looked up. He went by the name Hiro when he introduced himself; an earlier name: a country train guard, evidently, by habit if not by uniform. He had the thin, resilient way people get when they have been forced to carry others. "We were at the station," he said before Kai could ask. His voice had the slow, even cadence of someone who told bad stories often enough to stop them growing louder. "Sixteen of us when the light came."
Miri's hands stilled. She set down the torn scarf and folded it with a noise that was almost polite. "Sixteen," she echoed. "Hiro, you said sixteen."
Hiro nodded. "Riding into Tokyo. Late. Crowded platform. We were arguing about a seat when the sky—" He gestured with a hand that trembled a fraction. "It tore like paper. One moment we were there, next we were here on the ground and half of us—" He looked past Kai as if seeing the eaten parts of the number still being counted. "A pack came out of the dark. Like a wind that had teeth. They ate them before we could get out of the way."
Silence gathered like a flock. Kai listened to each breath as if it might be data mapped to a shape. "You saw them?" he asked.
"No," Hiro said. "We didn't really see the shape. Just movement. Smells. A sound like fabric being pulled over a mouth. They moved too fast—too neat. They were more like a thought than an animal. We scattered. Some of us ran into a market—turned a corner—and the light took them different. When the pack found the group they—" He made the motion with his knuckles, a clean snap of something being undone. "They did not leave much."
Miri swallowed. "We don't know what they look like," she added. "Only what they do."
A young woman with a scraped knee—one of the six survivors Hiro referenced—spoke up. "They cut the air like scissors," she said, and for the first time any of them, the lad's voice trembled visibly. "My brother—he was taken at the station. One moment he was there, the next his face—" She covered her eyes with the heel of her palm and did not finish.
Kai watched the way grief rearranged someone's features. It was a map to fragility. He felt a narrow thing twist in his chest that was not pity—he'd cataloged pity before—but recognition: the world produced pain in regular patterns and for regular reasons. If he could name the reasons, he could prevent them.
"You were all transported together," he said, turning the fact into a lever. "If you consent, I can register six names as Citizens. It will take a small part of whatever you call mana. In exchange you'll be under the tower's surveillance and defense vectors."
Miri's mouth opened. "So you're saying you'll… protect us?" Her voice carried the odd mixture of skepticism and a hope too large to fit into a single word.
"I'm saying this tower will feed on your output to become stronger," Kai said. "It will also give you a place to claim. Gardens, storage, rotation shifts—things that make survival less random."
There was a pause while everyone mentally balanced promises against the taste of the system in their ears. People wanted security but feared being owned, and Kai knew that ownership was a word with teeth. He did not like the moral taste of taking advantage, but he liked the necessity of trade. He had seen too many people die because they refused exchange.
Hiro's slow breath came out in a thin line. "We have little in the way of magic," he said. "Most of us—hard workers, station hands, teachers—nothing strong. If being listed means we live longer, then what's the cost?" His face tightened. The old stoic in him counted it like currency.
"You give consent," Kai said. "You keep your agency. The tower takes a portion of your output when you sleep—they call it allocation. You will be allowed work shifts. You keep possessions. If you die, the tower holds a memory and releases a small restitution. It improves defensive AI targeting. It reduces idle wear on installations."
Miri laughed then, brittle and half a sob, and everyone else itched with the noise of nerves. "He makes it sound like a warranty," she said. "Do you sell plumbing with that too?"
"Not plumbing," Kai answered, and because humor was a small, useful thing he added, "But a cistern. If we grow, you get roofs."
The group laughed for a little while, a jagged, thin sound that did not chase away the fear but supplied enough lightness to make movement possible. A child in the corner—silent until then—poked his head out and said, solemnly, "Do you have a tower for cats?"
Miri barked a laugh that ended in a wet sound and everyone looked toward the boy, who beamed because attention was its own currency. Kai felt the shape of the moment and made a decision that felt like an engineering choice rather than a moral one.
"All right," he said. "Hiro, Miri, name list." He reached into his jacket and tapped the inner seam where the system nested like a stubborn god. The voice—calm, mechanical—asked for confirmation. Kai spoke names aloud. "Hiro, Miri, Kenta, Sora, Yuna, Old Man Ito, Mei. Consent given?"
They murmured their assent, each word a tiny surrender and a bargain. The system chimed acceptance like a bell. "Citizens registered," it said. "Allocative parameter set. Tower defensive matrix scaled by 30%."
Kai folded his hands and for an instant let himself feel the small satisfaction of numbers aligning. Protection increased, the Sentinel's sweep widened fractionally, and the plain's overlay sharpened where their cluster lay. The success tasted of metal and the faint echo of someone else's laughter.
Hiro rested his hand on Kai's forearm, surprising in its firmness. "Kid," he said, "we owe you a roof."
Kai did not say it was his roof. He only nodded, a motion of acceptance. "We owe strategy," he corrected. "You owe to not die first. That's how survival works."
They set to work that day with the awkward choreography survivors find when they must both heal and prepare. Some collected resin. Some scouted the rim lines. Kai mapped the plain with the small clinical zeal of someone drafting a blueprint. At dusk, when the plain gathered its long shadows again, he would test the newly scaled defenses and learn how they bent under pressure.
Before night fell there was time enough for a small, ridiculous argument about whether a kettle could be used to boil resin, and Miri won it by threatening to kick the kettle if it refused to cooperate. Laughter carried into the low sun like a proof that even here, life insisted.
Kai listened. He watched the way the system adjusted to the new citizens, the slight smoothing of lag in the Sentinel's field. He tasted the trade-off: human warmth given as a resource to buy a chance at permanence. He had chosen the exchange because the numbers favored survival. He would watch them keep that trust.
When the day thinned and the first long shadows flung themselves like spears across the plain, Kai stood at the Sentinel and watched the horizon for movement. The system was quieter now, the voice in his pocket less insistent. He tightened his fingers on the concrete edge and thought of the people who had not survived the station—the sixteen reduced to six.
He thought, not of grief—of logistics. Patterns, again. If he could map where the predators favored, he could move people out of reach. If he could stagger watch schedules, he could buy days. If he could teach one small group to be precise—then more might live.
The world carved itself into problems and solutions. He liked being the man who made the sum work.
End of Chapter 4