It's the sixth part of the Harry Potter series, and Harry's in for a magical year.
It starts off with Dumbledore taking Harry to see an old professor who he is trying to persuade to return to Hogwarts as a teacher.
But when the new term arrives, Harry takes a N.E.W.T Potions class and discovers an unexpected secret in a borrowed book.
The main action happens near the end where Harry and Dumbledore try to recover something - a very dark object.
Harry, is the hero of course, with best pals Ron and Hermione.
Ginny, Fred and George come into the story a lot in this book.
And the villains - Snape, Malfoy and You-Know-Who.
The potion scenes are excellent as you can just imagine the look on Hermione's face.
And the scenes where Dumbledore and Harry go into a cave are gripping though a touch scary.
Any weak bits?
The first couple of chapters without Harry in are quite boring.
But afterwards the pace hots up and it's a JK Rowling classic.
Definitely! I read for three hours non-stop!
Sophie, 13, Gosport