Harry and his friends Ron and Hermione return for their third year at Hogwarts School of Witchcraft and Wizardry, where the teenagers are forced to face their darkest fears as they confront a dangerous escaped prisoner and the equally foreboding Dementors, who are sent there to protect them.Harry must overcome the Dementors, outsmart a werewolf and deal with the truth about Sirius Black and his relationship to Harry and his parents. With his best friends, Harry masters advanced magic, crosses the barriers of time and changes the course of more than one life.