[This whole place becomes more of a mess the higher they go and he can feel his heart start sinking into his stomach. Until they're met with a wall and a door, odd.]

Per... haps? Go on, open it. There's no sense in making questions while we can simply just open the door and find out instead.

[He's hoping there's an Actual Apartment here somewhere and that this wasn't some sort of weird gotcha moment that he wasn't aware of. Tsukikage is better than that, certainly...?]