Hit a bug. If you go down the stairs from the obvious trap room after the roof without the Delinquent, your character freezes and can't open the menu or anything. I'm guessing it tried to trigger the cutscene with the Delinquent in it and failed to.
It only happened once, though, every other time I've walked down the stairs it's been fine.










, not sure why, but here's a screenshot of what was going on when it happened.




