Hmmm...these guys are pretty sneaky. Hey Saihara-chan, did you check the lights on the walls? Maybe like...one of the screws is a button, or maybe the light is a button itself! I'll check these ones over here, okay?

[There are a number of plain looking light fixtures along the walls. If Shuichi investigates them, he'll find that....none of the screws do anything. But if he tries to pull or twist any of them, he will find one that turns just a little. Enough to make it seem like it's just loose in the wall mount, but he'll also hear a very soft beep to accompany it.

The door, however, doesn't open. But that's probably not normal?]