Department of Mysteries This is the floor where all the secrets, the unknowns, and the plain spookiest of all magical things are stored. It's torch-lit, silent, black and ominous; and as you step from the corridor into a circular room with a dozen doors set all around the walls, you know something isn't quite right. The moment the door is shut, there is a rumbling and a sense of movement in the dark, and the walls rotate.