Harry Potter's third year at Hogwarts begins under a shadow. Sirius Black, a convicted murderer and follower of Lord Voldemort, has escaped from the wizard prison of Azkaban, and all signs suggest he is coming for Harry. For once, the danger is taken seriously: the Ministry of Magic stations Dementors, the soul-sucking guards of Azkaban, around the school grounds, though their presence proves almost as threatening to Harry as the killer they are meant to keep out.
Amid the fear, Harry finds an unlikely ally in the new Defence Against the Dark Arts teacher, Remus Lupin, who knew his parents and begins teaching him to defend himself against the Dementors' influence. But between Hermione's impossibly full timetable, Hagrid's ill-fated debut as a teacher, and a divination professor who keeps predicting Harry's death, the year offers little peace. The truth about Black's escape is tangled up with the night Harry's parents died, and uncovering it will force Harry to question everything he thought he knew about their betrayal, and bring him closer to his family's past than he has ever been.
