"Sometimes you can go back, but sometimes the door locks behind you and that's it. If there's magic, it might not let you open more than one. Or you might be able to open all of them, but two of them contain wild animals."

He takes a step back, glancing between the doors as though he'll somehow be able to see something he isn't currently seeing.

"Or it could be a perfectly ordinary intersection. Maybe the doors cut down on drafts."