She could tell it was a book. She tugged at the thin velvet ribbon, and the paper fell away, revealing a pocket-sized Hogwarts: A History. She smiled, picking up the book to rifle through the familiar pages, but the book was hollow. Instead of pages, an intricate, detailed diorama of the Hogwarts library filled the space. It was beautiful. Setting it upright and open, she saw an undetectable extension charm had been applied, so the whole library was contained within the cover.