Harry’s first stop was the books on the war with Voldemort—he bought one copy of each. He also picked up a few books of curses and other fighting spells, a directory of British owl-order businesses, and a tiny monograph on house elves that looked like it had been in the store longer than the shelf it was sitting on. Thinking of the Invisibility Cloak in his bag, he looked through a shelf of books on upkeep of magical objects until he found one that included them; then he added a book on concealment magic to his basket.