In his third year at Hogwarts, Harry learns that a dangerous prisoner named Sirius Black has escaped from the wizarding world's most terrifying prison and may be coming after him. As the truth about Sirius, Harry's parents, and a long-buried betrayal slowly unravels, Harry must also contend with creatures that feed on despair. A more emotionally layered entry in the series that begins to explore themes of injustice and grief.