This is the fourth installment of the Harry Potter Series and this time Harry, Ron and Hermione is back in Hogwarts for the new semester. They have learned of the new Defense against the Dark Arts Teacher, Professor Lupin whom they met in the train to Hogwarts and the news about the escaped criminal, Sirius Black, loyal servant of Lord Voldermort from the prison of Azkaban.  Because Harry was the cause of Lord Voldermort’s death, the ministry of magic believes that Harry could be in danger as Sirius Black will sneak in to Hogwarts and try to avenge his master’s death. These believe bring about the installment of the awful Dementors around the school in the effort to capture Sirius Black. This is again a good series as the book reveals more about Harry’s parents’ death. Like the first two series, there is also the annual quidditch match, this time however the match was interrupted with the appearance of the Dementors that wind up attacking Harry.  In this book, Harry learned about his parents past, a secret map, the encounter of the Dementors and Sirius Black and being saved by patronus that drives the Dementors away.