"What aren't we in detention for?" he quipped back with a grin. "Professor Silver caught us raiding her classroom. Since Tris fessed up it was his idea, she handed him off to Quoft, so I'm sure whatever he's got was much worse than what I had."
Though it wasn't anything Tris couldn't handle. They'd probably have a story when he came back. Unless he'd got stuck just cleaning, too. What was it with cleaning? Didn't they have house elves to do that?