Lord Voldemort has returned, but the ministry of Magic is doing everything it can to keep the wizarding world from knowing the truth. They appoint Ministry official Dolores Umbridge as the new Defense Against the Dark Arts professor at Hogwarts. When Umbridge refuses to teach practical defensive magic, Ron and Hermione convince Harry to secretly train a select group of students for the wizarding war that lies ahead. A terrifying showdown between good...

Harry, Ron, and Hermione, now teenagers, return for their third year at Hogwarts. There they are forced to face escaped prisoner Sirius Black, who poses a great threat to Harry. Harry must overcome the threats of Dementors, outsmart a werewolf, and finally deal with the truth about Sirius and his relationship with his parents. Harry and friends master advanced magic classes, cross time barriers, and change the course of more than one life.