Harry Potter and the Prisoner of Azkaban
A crisis is brewing at Hogwarts. A prisoner named Sirius Black has escaped from Azkaban, where he has been held for 12 years for killing 13 people. He is said to be the heir apparent to the Dark Lord, Voldemort. Black is headed for Hogworts, and Harry Potter is no longer safe. There may even be a traitor at the school.