You've entered the library of the Unseen University. Whether or not you were even allowed in the University, much less the library, is entirely known to you. Certainly not the wizards who are all too busy with something or other to have noticed you sneaking in the most inconspicuous manner. So far the only one to have even registered your presence is The Librarian. Or at least from what you've heard the very large hairy individual hanging from one of the bookshelves staring down at you is.