The Edge of Equilibrium

Chapter 4: Third-Party Observation

The days that followed carried a heavier weight than usual. Ever since that cold instruction, Mio was the only one who came through the sliding door of Physics Laboratory No. 13 now.

She came carrying a few folders Masato had passed along. There were still some technical findings from forensics the police couldn't fully make sense of, and Masato had specifically asked Mio to bring them to the professor.

"This is the residue analysis from the ventilation system, Professor," Mio said, setting a green folder on the neatly kept desk.

Reiji didn't answer right away. He looked up from the electron microscope, took the folder, and opened it. No greeting. No small talk about the weather. Not even a word passed between them about the case. He turned the pages one by one, expression flat and rigid, eyes scanning quickly across rows of figures and chemical structures.

Once he found what he needed, he picked up a pen and jotted down a few lines of equations along with a brief note, eyes still moving across the documents in front of him.

But Mio, as a detective, was in the habit of noticing small things.

Standing across the desk, she studied the physicist's face. On the surface, Reiji looked exactly the way everyone always described him: cold, untouchable, entirely rational. But somehow, behind the silver-framed glasses, Mio caught something dim, something faint. The professor looked... sad.

Once he'd finished writing, Reiji handed it over. Mio slipped the note into her bag slowly, her head full of questions. She genuinely couldn't understand why Reiji had suddenly forbidden Masato from coming here.

Her mind drifted to a conversation she'd had with Masato a month back, before any of this, over lunch at the station cafeteria. He'd talked about his university days, his eyes bright with a proud kind of nostalgia.

"My friend's cold, way too particular about details. Meet him once and you'd probably think he can't read people at all," Masato had said, laughing quietly as he stirred his coffee. "But he's not a bad person at all. He's just too logical, Aizawa-san. Too logical for a world this messy."

He'd said something like that more than once. To him, Reiji was a close friend he leaned on, someone who never changed no matter how much time passed between their conversations. So why would Reiji suddenly wreck it on purpose, out of nowhere?

"If there are no other variables to analyze, you're free to go, Detective Aizawa."

Reiji's low voice pulled her back. She bowed her head quickly. "Understood, Professor. Thank you for your help."

She turned and headed for the door. But right before her hand reached the handle, curiosity got the better of her, and she glanced back once more.

What she saw stopped her cold.

Reiji hadn't gone back to his laptop. The man who always looked busy, who never wasted a second on anything inefficient, stood frozen instead by the window overlooking the parking lot. His hands were tucked into the pockets of his white coat, eyes fixed on the darkening evening sky.

His shoulders had dropped, just a little. He stayed like that for a long time, letting the room's silence swallow him up, as if some invisible hole had punched straight through his chest. No physics equation was running through his head right now. Mio could see the emptiness in the way he stood.

She stayed quiet. She didn't say a word to break his reverie, and he didn't even seem to notice she was still standing in the doorway. But as she finally stepped out and slid the door shut behind her, she realized something her senior had completely missed.

Reiji Kanzaki might really be too logical for his own good. But the lonely silence filling that laboratory was proof enough: the genius was up against a problem no logic on earth could solve.