Harry Potter and the Prisoner of Azkaban

Harry Potter and the Prisoner of Azkaban is a fantasy novel by British author J. K. Rowling. The third novel in the Harry Potter series, it follows the young wizard Harry Potter during his third year at Hogwarts School of Witchcraft and Wizardry. With his friends Ron Weasley and Hermione Granger, Harry investigates Sirius Black, an escaped prisoner who is believed to be one of Lord Voldemort's allies.