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 Azkaban 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 be a traitor in their midst.

This gorgeous new edition in celebration of the 20th anniversary of the publication of Harry Potter and the Sorcerer's Stone features a newly designed cover illustrated by Caldecott Medalist Brian Selznick, as well as the beloved original interior decorations by Mary GrandPr .