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. The book was published in the United Kingdom on 8 July 1999 by Bloomsbury and in the United States on 8 September 1999 by Scholastic, Inc. The book, which took Rowling one year to write, sold 64,000 copies in just three days after its release in the United Kingdom, and since has sold over three million in the country.