What happens at the end of Harry Potter and the Prisoner of Azkaban?

Answer 1

Harry and Hermione go back in time (which also explains how she kept popping up in class.) They save Buckbeak from execution. Harry then performs a full patronus to stop the dementors giving Sirius and Harry the kiss. The minister eventually captures Sirius and makes him wait in a chamber where Sirius waits to receive the "kiss." Harry and Hermione take him out of there and let him escape on Buckbeak. Lupin resigns as a teacher since word spread that he was a werewolf and he gives Harry back the Maurador's Map.

Answer 2

At the end of Harry Potter and the Prisoner of Azkaban, Sirius Black is revealed to be innocent, Peter Pettigrew escapes, and Harry learns about his family's history. Sirius gives Harry a magical map called the Marauder's Map as a gift before leaving. Time-turner is used to save Buckbeak and Sirius.