The locker room smelled like floor cleaner and old sweat and the specific staleness of a room that never got enough air. Do-yun had changed for gym in four minutes, which was faster than most of the other students, which meant he was almost alone by the time the door opened again.
Almost.
The boy from the stairwell walked in like he owned the floor plan.
He was bigger than the distance had suggested — not the chest-forward aggression of the guy from class, but something quieter and more deliberate. Third-year. Maybe 180 centimeters. The kind of build that had been developed rather than inherited, which meant discipline, which meant he was more dangerous than someone who was simply big. He had a small scar along the jaw that had healed clean, which told Do-yun it had been treated properly, which told him this wasn't someone who got hurt by accident.
He didn't rush. He came in, checked the room the way Do-yun checked rooms — a single sweep, exits and occupants, and then walked to the bench across from Do-yun's locker and sat down.
Do-yun kept his eyes on his locker. He finished putting on his gym shirt.
"New kid," the boy said.
"I've heard that one already today." Do-yun closed his locker. "Does everyone here use it or just the people with nothing else to open with?"
The boy looked at him. Not offended. Recalibrating, the same way the bulletin board boy had recalibrated, but this one did it faster and with less emotion, which meant he'd had more practice encountering things that didn't respond the expected way.
"You were in the east wing, second floor, during lunch," he said.
"I got lost."
"New kids get lost on the ground floor. They don't get lost on the second floor of a wing they have no classes in."
Do-yun looked at him for the first time directly. "I was looking for the bathroom."
"The bathrooms are marked on every floor." The boy leaned forward, elbows on knees, casual. "Try again."
Do-yun said nothing. Sometimes silence was its own answer, and the answer was: I'm not giving you anything to work with.
The boy studied him for a moment. Then he looked him over — not threateningly, or not only threateningly. There was something clinical in it, an assessment, the way a carpenter looked at a piece of wood to understand what it could and couldn't hold.
"How much do you weigh?" he said.
Do-yun kept his expression even. "Why?"
"Because I'm trying to understand what I'm looking at." He tilted his head slightly. "You're what — fifty kilos? Maybe fifty-five if you ate a big breakfast. First year. Transferred in alone, mid-year, which people don't do unless something pushed them or something pulled them." A pause. "And you walked down that hallway on your first day, which people don't do unless they're very stupid or they're looking for something specific."
"I told you. I got lost."
"You don't seem like someone who gets lost."
The locker room was now empty except for the two of them. Do-yun had noted this when the boy came in — had tracked the last of the other students filing out, had calculated the acoustic range of the room, and had identified the two exits. Old habit. New necessity.
"I don't know what you think you saw," Do-yun said, "but I'm a transfer student who has been here for one day. I don't know anyone, I don't know anything, and I'm not involved in whatever it is you think I'm involved in."
He said it well. He knew he said it well — the right pace, the right words to cause mild confusion, the exact tone of someone slightly annoyed at being accused of complexity they didn't have. He'd practiced versions of this kind of sentence for exactly this kind of moment.
The boy looked at him.
And smiled, very slightly, in a way that meant he'd heard the performance and found it competent but insufficient.
"You're good at that," he said.
Do-yun said nothing.
"The voice thing. The face thing." He gestured vaguely. "Someone taught you how to sound like that? Or you taught yourself, which is more interesting." He stood up from the bench, and the shift in his height changed the geometry of the room in a way Do-yun noticed automatically. "But your eyes do something when you're working out what to say. Just for a second. Right before the answer comes out." He took one step closer. "Most people wouldn't catch it."
Do-yun held still.
"But I'm not most people," the boy said. "And neither are you, which is the problem."
He was close now. Not aggressive — worse, somehow. Conversational. Like they were discussing something mutually understood.
"I don't know what you found in that hallway," he said quietly. "And I don't need to know. What I need is for you to understand something clearly so we don't have to have this conversation again."
Do-yun opened his mouth.
A punch came without wind-up, without any of the telegraphing tells he'd been unconsciously cataloguing in preparation for the conversation going wrong. A short, precise shot to the stomach, not full force. Calibrated exactly to the threshold, this will not put you on the floor, but you will feel it for the rest of the day. His breath left him completely. He folded forward slightly and caught himself on the locker with one hand and breathed, or tried to, while his diaphragm argued with him about the timeline.
The boy leaned in close. His voice dropped to just above nothing.
"We have eyes and ears in every corner of this school." A pause, letting the words settle. "Every corner. Every floor. Every conversation that happens in a space it shouldn't happen in." Another pause. "You're small. You're new. You don't have a name here, you don't have a crew, and you don't have anything that makes you worth the trouble of paying attention to." His voice was almost gentle. "So be a good student. Attend your classes. Eat your lunch. Go home." He straightened up. "Be a nobody like everyone else who knows better. And whatever you think you're doing — stop."
Do-yun stayed where he was, hand against the locker, breathing returning in increments. He heard the door open and then close.
He stood up straight.
His stomach hurt in a way that told him the aim had been deliberate and the technique had been practiced. Whoever that was, he'd done this before. Not as anger. As communication.
Do-yun pressed his back against the locker, looked at the ceiling, and ran through everything that had just happened with the cold, even attention he gave to everything he needed to learn from.
The punch had come from the right side, with a slightly upward angle, meaning the boy was right-handed and had practiced short-range strikes. He'd kept his feet planted, no weight shift before, which was the reason Do-yun hadn't seen it coming — he'd been watching feet and hadn't finished mapping the upper body yet.
He pushed off the locker, rolled his shoulders, and checked his expression in the small mirror above the sink. Neutral. Good. He adjusted his gym shirt and picked up his bag.
The boy had told him to stop. To be a nobody. To disappear back into the noise of a school full of kids who had figured out that the best survival strategy was not to see anything.
Do-yun thought about the notebook in his bag. Min-jun's handwriting. I don't know who I can tell. The two men at the back of the funeral home.
He thought about the voice through the propped door. The music kid is not a concern anymore.
His brother had been careful. His brother had been smart. His brother had found something real and had still ended up on that roof, and the reason — or one of the reasons, the first domino — was that he'd been working alone in a building full of eyes and ears and hadn't known it until it was too late.
Do-yun was not going to make the same mistake.
He was going to need to be something other than a nobody. He was going to need to build something — cover, position, relationships, the kind of presence in this school that made being watched a two-way street. He was going to need to learn how to move through the kind of organization that had someone like that watching a stairwell, and he was going to need to learn it from the inside.
He was fifteen years old, fifty-something kilos, and he had no crew and no name that mattered.
He needed to fix that.
He walked out of the locker room and down the corridor toward the gymnasium and by the time he pushed through the door, his face was completely ordinary — just a new student, slightly late, finding a spot in the back of the class.
A nobody. For now.
But Do-yun had always been better at building things than people expected, and he had started from worse positions than this.
He just had to be patient, precise, and willing to do what needed doing.
His stomach hurt the entire period. He used it to stay focused.