Harry Potter and the Prisoner of Azkaban
Harry Potter flees the Dursley home when he magically inflates his Aunt Marge like a balloon and causes her to float away in a pique of anger after she insults his father. He is rescued by the Midnight Bus, which services wizards, and brought back to Hogwarts. However he is warned that a dangerous criminal, Sirius Black, has escaped from Azkaban Prison and is lurking in the area. Sirius Black was an associate of Lord Voldemort and it is believed he is coming to kill Harry. Meanwhile the fearsome Dementor guards from Azkaban are brought in to watch over the school, but prove something as terrifying as the threat of Sirius Black when they touch Harry's mind.