"Harry Potter and the Prisoner of Azkaban" is a fantasy novel written by British author J. K. Rowling and is the third in the "Harry Potter" series. The book follows Harry Potter, a young wizard, in his third year at Hogwarts School of Witchcraft and Wizardry. Along with friends Ronald Weasley and Hermione Granger, Harry investigates Sirius Black, an escaped prisoner from Azkaban, the wizard prison, believed to be one of Lord Voldemort's old allies.

Lord Voldemort is a sobriquet for Tom Marvolo Riddle, a fictional character and the main antagonist in J. K. Rowling's series of Harry Potter novels. Voldemort first appeared in "Harry Potter and the Philosopher's Stone", which was published in 1997. This character appears either in person or in flashbacks in each book and its film adaptation in the series except in the third one, "Harry Potter and the Prisoner of Azkaban" (published in 1997), in which he is only mentioned. In the fourth book of the series, "Harry Potter and the Goblet of Fire", Voldemort reappears at the start and the climax of the book.

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