Alternity

 
Please avoid the third corridor on the fourth floor until further notice, as Peeves (that would be our resident poltergeist, for you first-years) has discovered how to redirect the pipes from the boys' toilets on the fifth floor. It's really quite unpleasant at the moment, so you'd do best to stay out of the area until I've had a chance to get after the mess.

Also, would Messrs. Weasley the Identical please call by my cottage at their earliest convenience? I've recovered something of theirs that I would like to return to them, and I would trust them to be a bit more careful with it in the future. It's quite valuable.