Loved this book. The series got much darker in this book. Lots more issues were brought up. I found it to be "The Empire Strikes Back" book of the series. Had a lot more darkness in the story and the ending was not all happy go lucky that the last two were. I also really liked the addition of the Dementors. Only hinted at in the 2nd book when they were brought into the story they became (In my opinion) a very nice satire for mental health Eg. Anxiety. They effect Harry worse because of his past experiences (PTSD) and the way that Harry is taught to deal with them is directly focused on positive thinking....... A hint at the idea of CBT (in a way of putting it that someone of the target audiences age would understand). Anyhow a delightfully flowing story, already picked up the 4th one.