Author J.K. Rowling
Series: Harry Potter #3
Publisher Arthur A. Levine
Publication Date September 8, 1999
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 well be a traitor in their midst.
Another thing I didn’t realize before now is that however slightly has the underlining of prejudice in the plot. I believe this is shown through Professor Lupin, whose true nature is of a werewolf which is why he’s been missing classes. Remus is described as having shabby dress with dark circles under his eyes. Somewhere in the book he is commented as saying that it is difficult for him to hold a job and after transforming, and putting students at risk, resigns from the post because “parents wouldn’t want their children being taught by someone like me.” Maybe I’m reading too much into this but I thought this was an interesting analogy towards racism or discrimination.