Harry Potter and the Prisoner of Azkaban opens on the night before Harry's thirteenth birthday, when he receives gifts by Owl Post from his friends at school. The next morning at breakfast, Harry sees on television that a man named Black is on the loose from prison. At this time, Aunt Marge comes to stay with the Dursleys, and she insults Harry's parents numerous times. Harry accidentally causes her to inflate. Harry leaves the Dursley's house and is picked up by the Knight Bus, but only after an alarming sighting of a large, black dog. The Knight Bus drops Harry off at Diagon Alley, where he is greeted by Cornelius Fudge, the Minister of Magic. He rents a room and awaits the start of school. In Diagon Alley, Harry finishes his schoolwork, admires a Firebolt broomstick in the window of a shop, and after some time, finds his friends Ron and Hermione. At a pet shop, Hermione buys a cat named Crookshanks, who chases Scabbers, Ron's aging pet rat. Ron is most displeased. The night before they all head off to Hogwarts, Harry overhears Ron's parents discussing the fact that Sirius Black is after Harry.