I have to say upfront that Harry Potter and the Prisoner of Azkaban is easily my favourite of the Harry Potter books, so this review is likely to be extremely biased but I shall try to remain objective! Harry is in his third year at Hogwarts, and the big news is the escape of Sirius Black from Azkaban prison, a dangerous and deadly wizard. Harry learns that, for some reason, Sirius is after him. Due to the increased security at Hogwarts, Dumbledore has reluctantly allowed the Dementors - ghostly cloaked beings that suck the happiness from a person's soul and eventually drive them mad - to guard the castle. The book uncovers the mystery of who Black is and why he is so keen to find Harry at Hogwarts, while also dealing with the regular shenanigans of a Hogwarts school year.
This book is where Rowling tightens up her act, in my opinion. The plot is excellently written with not too many of the loopholes that characterised the earlier two books. The use of the Time Turner was not too much of a McGuffin, especially since Hermione had been using it already during the school year. It was sleek and not too long, a fault of her later books. I enjoy reading Harry Potter books, but the later books definitely suffer from being longer than a few hundred pages. Here Rowling is forced to be efficient with her story, and it is all the more effective for it.
By now the wizarding world is firmly established, but Rowling still manages to spice up the book with many lovely little details. We hear more about the lessons taken by the children, and some new classes are introduced, such as Care of Magical Creatures and Divination. Some of the little details are my very favourite moments in the book, such as when Hermione achieves over three hundred percent in her Muggle Studies class. I also love the throwaway line from during Ron and Harry's Charms exam: "Hermione had been right; Professor Flitwick did indeed test them on Cheering Charms. Harry slightly overdid his out of nerves and Ron, who was partnering him, ended up in fits of hysterical laughter and had to be led away to a quiet room for an hour before he was ready to perfom the Charm himself." This always makes me giggle.
The village of Hogsmeade is another charming addition to Hogwarts, what with the sweet shop and the pub serving Butterbeer (which sounds delicious!). I do wonder at the fact that Hogsmeade has never been mentioned in two previous books though! Sometimes Rowling decides to add in features that have never cropped up previously and it can be a little jarring.
And she does love the big reveal! Here we have Sirius and Lupin going over the events of twelve years ago AND covering some of their school days, including why Snape hates them so, in a long dialogue-heavy section. I feel that this could have been spread out across the book in a better way, so that it didn't come across as much as an explanation to bring us (the reader) up to speed.
There were some wonderful new characters, such as Professor Lupin - I have always wished that he could have continued as the Defence of the Dark Arts teacher. However, I did not like Professor Trelawny much at all - the scenes in her classroom were dull and dragged for me.
Finally, I would comment on the fact that Rowling cannot seem to write an exciting Quidditch match - they all seem to be Lee Jordan commenting on players throwing the ball to each other, and then Harry catches the Snitch in some weird and wonderful way. Mind, I don't think it would be easy to write an interesting football or rugby match into a novel either - they are just too dynamic for the written word.
These are very minor niggles. In my view this is a richly entertaining and imaginative story, in which the main characters really develop. I appreciated the strong plotline. I cannot wait to read the next one!