Thanks Deyve, but maybe stuck was the wrong word for me to use, my Ranger is the only one in there, and she can just Escape out or teleport out with ease. However this doesn't solve the mini-quest. Every experience point seems to be necessary in this game, so I'd like to solve this quest instead of just avoiding it entirely.
Also apparently I need to learn how to make the [Spoiler] hidden thing in forums, that's nice.

I don't see any buttons except for the one I mentioned, nothing near the door, only a few smoke vents in the floors and red vents in the walls, none of which can be interacted with aside from blocking the floor vents with objects.