哈利·波特在霍格沃茨魔法學校已經度過了不平凡的兩年，而且早已聽說魔法世界中有一座守備森嚴的阿茲卡班監獄，裡面關押著一個臭名昭著的囚徒，名字叫小天狼星布萊克。傳言布萊克是“黑魔法”高手伏地魔——殺害哈利父母的兇手——的忠實信徒，曾經用一句魔咒接連結束了十三條性命。不幸的是，布萊克逃出了阿茲卡班，一心追尋哈利。布萊克在睡夢中仍然囈語不休：“他在霍格沃茨……他在霍格沃茨。”
哈利·波特雖然身在魔法學校的城堡內，既有朋友的赤誠幫助，也有老師的悉心呵護，但校園內危機四伏，哈利的生命時時受到威脅。**，布萊克終於站到了哈利的面前……

Harry Potter, along with his best friends, Ron and Hermione, is about to start his third year at Hogwarts School of Witchcraft and Wizardry. Harry can't wait to get back to school after the summer holidays (who wouldn't if they lived with the horrible Dursleys?). But when Harry gets to Hogwarts, the atmosphere is tense. There's an escaped mass murderer on the loose, and the sinister prison guards of Azkaban have been called in to guard the school ...