ooh true. Maybe some sort of riddle where they have to get to know each other to answer it. They each have pieces of the riddle that pertain to the other one. A confessions sort of thing. They answer correctly and they get a clue to getting themselves out (like maybe a number for a combination on a lock that they can only try to open twice). They answer in correctly or the other one answers for them poison gas gets put into the room. Enough gas and they're dead. They try the lock more than twice and the room fills with gas.

IDK any ideas on designing one?