虽然纽特（埃迪·雷德梅恩 Eddie Redmayne 饰）协助美国魔法部将邪恶的黑巫师格林德沃（约翰尼·德普 Johnny Depp 饰）捉拿归案，但最终格林德沃还是逃脱了禁锢，他来到了法国巴黎，一是为了集结信徒掀起革命，二是为了寻找同样藏匿在这里的克雷登斯（埃兹拉·米勒 Ezra Miller 饰），寄生在克雷登斯身上的默默然是帮助格林德沃实现野心的不可或缺的道具。
格林德沃的潜逃在整个魔法世界里都掀起了轩然大波，一时间草木皆兵。邓布利多（裘德·洛 Jude Law 饰）秘密的找到了纽特，希望他能够前往巴黎，先格林德沃一步找到克雷登斯。和纽特一起踏上巴黎之旅的，是麻鸡雅各布（丹·福格勒 Dan Fogler 饰），他此行的目的，是要找回先前因为吵架而来到巴黎投奔姐姐蒂娜（凯瑟琳·沃特森 Katherine Waterston 饰）的恋人奎妮（艾莉森·苏朵儿 Alison Sudol 饰）。

Harry Potter has to sneak back to Hogwarts, after accidentally inflating his horrible Aunt Petunia. But once there everyone is whispering about a prizoner who has escaped from the famous wizard prizon, Azkaban. His name is Sirius Black, and as a follower of Lord Voldemort he is determined to track Harry Potter down - even if it means laying siege to the very walls of Hogwarts!

In one of the most hotly anticipated sequels in memory, J.K. Rowling takes up where she left with Harry s second year at the Hogwarts School of Witchcraft and Wizardry. Old friends and new torments abound, including a spirit named Moaning Myrtle who haunts the girl s bathroom, an outrageously conceited professor, Gilderoy Lockheart, and a mysterious force that turns Hogwarts students to stone.

Harry Potter has never played a sport while flying on a broomstick. He's never worn a Cloak of Invisibility, befriended a giant, or helped hatch a dragon. All Harry knows is a miserable life with the Dursleys, his horrible aunt and uncle, and their abominable son, Dudley. Harry's room is a tiny cupboard under the stairs, and he hasn't had a birthday party in ten years.
But all that is about to change when a mysterious letter arrives by owl messenger: a letter with an invitation to a wonderful place he never dreamed existed. There he finds not only friends, aerial sports, and magic around every corner, but a great destiny that's been waiting for him... if Harry can survive the encounter.

哈利波特（丹尼尔•雷德克里夫 Daniel Radcliffe 饰）结束了假期，即将回到霍格沃兹继续学习魔法。一个叫多比的家养小精灵警告哈利不要回到霍格沃兹，否则会陷入极大的危险。哈利没有听从多比的劝告，回到了霍格沃兹。很快，霍格沃兹发生了一连窜怪事:接二连三出现学生被石化，一直找不出原因。而哈利总能听到一种奇怪的声音，从墙壁里传出来。
传说，霍格沃兹有一个密室，里面记录着伏地魔年轻时的秘密，只有斯莱特林的人才能打开密室。哈利偶然发现自己能听懂蛇说话，一时传闻是哈利打开了密室。难道多比所指的危险就隐藏在密室？

逃过摄魂怪的追杀，通过魔法部的审查，哈利（丹尼尔·雷德克里夫）终于回到美丽的霍格沃兹。然而这个学期并不轻松，他不仅要完成魔法等级考试，还要应对夜晚的噩梦和黑魔法防御课老师乌姆里奇的打压。在好友的支持下，哈利秘密组建了邓不利多军团，与大家一起练习黑魔法防御术。
噩梦中，哈利总是以伏地魔的视角出现，似乎他们之间有着某种神秘的联系。在邓不利多（迈克尔·刚本）的指示下，哈利向斯内普教授（阿伦·瑞克曼）学习封闭术，却鲜有成效。终于在一次噩梦的诱使下，哈利偏执的赶往魔法部营救小天狼星，却不想陷入伏地魔的圈套，引发凤凰社与食死徒之间的正面冲突。在混战中，小天狼星（加里·奥德曼）不幸遇难。
究竟哈利与伏地魔（拉尔夫·费因斯）之间有着怎样的联系？在悲恸中，邓不利多为哈利揭开谜底，哈利还有更长、更艰难的路要走……