Year three at Hogwarts means new fun and challenges as Harry learns the delicate art of approaching a Hippogriff, transforming shape-shifting Boggarts into hilarity and even turning back time. But the term also brings danger: soul-sucking Dementors hover over the school, an ally of the accursed He-Who-Cannot-Be-Named lurks within the castle walls, and fearsome wizard Sirius Black escapes Azkaban. And Harry will confront them all.

As Lord Voldemort tightens his grip on both the Muggle and wizarding worlds, Hogwarts is no longer a safe haven. Harry suspects perils may even lie within the castle, but Dumbledore is more intent upon preparing him for the final battle fast approaching. Together they work to find the key to unlock Voldemorts defenses and to this end, Dumbledore recruits his old friend and colleague Horace Slughorn, whom he believes holds crucial information. Even as the decisive showdown looms, romance blossoms for Harry, Ron, Hermione and their classmates. Love is in the air, but danger lies ahead and Hogwarts may never be the same again.