Harry is returning to Hogwart's aware that escaped mass murderer Sirius Black is coming for him. With Hagrid in trouble for having an out of control Hippogriff and the Dementors who are hunting Sirius taking a dangerous interest in him, Harry is having a difficult year. But it gets worse when he realises that Sirius, his godfather and father's best friend, is responsible for the death of his parents.
This book begins the dark journey that Harry will be following through the rest of the series and introduces two of my favourite characters Sirius Black and Remus Lupin. Harry begins to grow up and understand that his world is a dangerous one and learning how to defend himself is a priority. I love this book and the development of the plot and characters. As usual Snape is brilliantly evil, and I liked the sinister stalking of Harry that seems to be taking place. Hagrid's teaching is somewhat unconventional to say the least and no doubt it will get worse as time goes on. The map is an excellent addition for rulebreakers and those Dementors really gave me the creeps. We start to get the true story of what happened to Lily and James the night they died and get an idea of their time at Hogwarts, which I'd love to read more about. Voldemort is no longer the vague seeming threat from the first two books. We start to see that he is going to be a brutal and dangerous enemy as the series progresses. By this book I was really addicted to this series!