Harry's scowl just deepened, and he twisted at the tap again, then reached into the filling sink, trying to unclog the drain. Though there was nothing there. The water was just. . . staying.
He stepped back as it started to spill onto his shoes. Perfect.
The rush of water seemed to be coming from all of the sinks, now that he looked. Not just the two they'd used, but the other three as well. And a slosh of water came from the toilets too.
Harry's nose wrinkled. "Sod it, Filch can deal with it." That was his job, after all. Or the elves or something. Hermione would probably raise a fit if she heard him assuming house elves should just magically clean up someone else's messes - but he didn't care. It wasn't like they didn't like working anyway.
This was probably some stupid prank from Peeves. Or maybe Myrtle trying to get attention.
He turned to leave. However, fate didn't seem to be cooperating, since the door was jammed very firmly shut while the water rapidly spread over the floor.