In the summer before his third year at Hogwarts, Harry Potter becomes fed up with his horrible aunt and runs away. Unfortunately, there's much more danger in the wizarding world than Harry thought. Convicted murderer Sirius Black has escaped from the wizarding prison of Azkaban. Black is known as one of Lord Voldemort's most devoted followers, and rumour swirl that he's coming after Harry to avenge Voldemort and finish the job. But everything is not as it seems with speculation of a traitor inside Hogwarts.