The first hour passed in chaos.
Some tried to force open locked compartments. Others checked ventilation, walls, pipes. It felt like the tower had a life of its own — with every creak, rattle, and dull thud, it was as if it were watching us.
"Takumi, we have a problem," said Kazuki, one of the few I could trust. "Sei has a headache. Her breathing's getting uneven. Three others report chest tightness."
I looked at the screen. The message at the bottom wasn't a metaphor.
> "In this tower, even the air can be a weapon."
"Evacuate?"
"There's nowhere to go," he reminded me. "We're sealed in."
I went to the ventilation block. Old pipes. Damp walls. The filters had something black in them. I collected a sample and sealed it in a lab container — the tower had provided a basic set of research tools. Too convenient. Too suspicious.
At that moment, a new message appeared on the screen:
> "Air safety level on Floor 1: unstable. Risk of worsening conditions — high.
You may request assistance from other floors. Responses are not guaranteed."
I looked at Kazuki.
"Prepare a request. Ask for filters. Don't mention the symptoms, just say we need equipment for diagnostics. Keep it polite — it needs to look like a routine exchange."
He nodded.
"Which class should we contact?"
I thought.
> 2-C was too unpredictable.
2-B — the weakest link, they might not reply at all.
2-A…
"2-A," I said. "Ai Sanada promised to help. Let's see how far that promise goes."
Twenty minutes later, a reply came.
> "Class 2-A agrees to provide filters. In return, we ask you to analyze the air on Floor 2 for the next 12 hours and submit a report through the system. The exchange will take place in the transition zone between floors."
"We accept," I said.
"You sure?" Mina asked. She stood nearby, a little apart from the group. "What if it's a trap?"
"Then I'll use the rules to strike back," I replied. "But for now — it's a test. If they help us now, we'll know they're serious about the alliance."
The exchange went smoothly. The filters arrived. Within an hour, the air began to stabilize.
But the tower wasn't asleep.
A new message appeared on the screen:
> "Next task begins in 3 hours.
Floor 1: Someone among you claims to know the truth about what's happening.
Find them. Or they'll find you."
Mina whispered softly:
"Psychological pressure?"
"We'll need to check everyone," I said. "And figure out who's playing a different game."