Department of Mysteries

The Department of Mysteries is a part of the Ministry of Magic that studies enigmas such as death, time, space, thought and love, and stores the records of prophecies. The wizards who work there are called Unspeakables, and their identities are kept secret. In Order of the Phoenix, Voldemort plots to obtain the full prophecy about himself and Harry stored there, and the battle in the department ends with the death of Sirius Black.