Harry Potter and the Prisoner of Azkaban.

I read the third book of this series, all 450 pages of it, and the entire series has failed to bore me as I read through all the books for a fifth time. In this, Harry meets someone who escaped from the wizard prison Azkaban. Harry helps Sirius Black (The prison escapee) after the Dementors capture him. They travel back through time to prevent his capture (paradox much?). Using his special ability, morphing into a black dog, they escape the dementors using a spell (the only spell that affects the dementors) and hiding in a magical home that only can be seen by certain people. Overall, I would give this book a 4.7 and recommend it to anyone who's read any of the Harry Potter books.