The stairs up and down don't appear to have clickable transitions. I'm sure they must, and there are some people who see them, but I don't. WASD walking through doesn't trigger either.
Also leaving the front door of the House of Heroes put me behind the door to The Last Stand down in Dunwarren - Devastated, Hazy Ruin. This The Last Stand door is locked, so it acts as a cozy little prison that can't be left. I know, third time getting myself stuck. On a roll tonight!