Professor Lupin: Come in. Now, I haven't the faintest idea Harry how this map came to be in your possession, quite frankly I am astounded that you didn't hand it in. Did it never occur to you that this in the hands of Sirius Black is a map to you?
Harry: No, sir.
Professor Lupin: No. You know, your father never set much store by the rules either. But he and your mother gave their lives to save yours. And gambling their sacrifice by wandering around the castle, unprotected, with a killer on the loose seems to me to be a pretty poor way to repay them. Now, I will not cover for you again, Harry, do you hear me? I want you to return to your dormitory and stay there. And don't take any detours. If you do, I shall know.
[taps the map]
Professor Lupin: I shall know.