Harry Potter and the Prisoner of Azkaban (Book 3) by J. K. Rowling

For twelve long years, the dread fortress of Azkaban held an infamous prisoner named Sirius Black. Convicted of killing thirteen people with a single curse, he was said to be the heir apparent to the Dark Lord, Voldemort.Now he has escaped, leaving only two clues as to where he might be headed: Harry Potter's defeat of You-Know-Who was Black's downfall as well. And the Azkban guards heard Black muttering in his sleep, "He's at Hogwarts...he's at Hogwarts."Harry Potter isn't safe, not even within the walls of his magical school, surrounded by his friends. Because on top of it all, there may well be a traitor in their midst. Illustrated by Mary GrandPré Publisher : Scholastic Paperbacks (October 1, 2001) Language : English Paperback : 448 pages ISBN-10 : 0439136369 ISBN-13 : 978-0439136365 Item Weight : 10.2 ounces Dimensions : 5.2 x 1.2 x 7.5 inches