- Harry, Ron, and Hermione return to Hogwarts for their third year.
- A new Defense Against the Dark Arts professor, Remus Lupin, joins the staff.
- Several mysterious incidents occur at Hogwarts, including attacks by a creature known as the Grim.
- Harry learns more about his parents' past and the truth about the traitor who betrayed them to Voldemort.
- Sirius Black, a supposed ally of Voldemort's, escapes from Azkaban prison.
- The Triwizard Tournament is held at Hogwarts, and Harry is unexpectedly chosen as a contestant.
- Harry faces several dangerous challenges during the tournament, including battling dragons, merpeople, and a giant maze.
- Voldemort returns to power, and the Battle of Hogwarts takes place, resulting in the deaths of several characters, including Cedric Diggory and Alastor Moody.
- Harry and his friends form a secret society called the Order of the Phoenix to oppose Voldemort and his Death Eaters.
- Harry learns more about his connection to Voldemort and the prophecy that links their fates.
- The Ministry of Magic refuses to acknowledge Voldemort's return, leading to a conflict between Harry and the Minister of Magic, Cornelius Fudge.
- The Order of the Phoenix faces several challenges, including the capture of Sirius Black by the Death Eaters.
- Harry finds a mysterious potions textbook that once belonged to a student known as the "Half-Blood Prince."
- The book contains valuable tips and instructions that help Harry excel in his potions class.
- Harry also discovers more about the past of Voldemort, including his connections to the Gaunt family and the Horcruxes, objects that contain pieces of Voldemort's soul.
- Draco Malfoy becomes a Death Eater and attempts to assassinate Dumbledore, but Snape intervenes and kills Dumbledore instead.
- Harry, Ron, and Hermione go on a quest to find and destroy the remaining Horcruxes to defeat Voldemort once and for all.
- They face many dangers along the way, including encounters with Death Eaters, Inferi, and other dark creatures.
- The group eventually locates and destroys the Horcruxes, leading to the final confrontation with Voldemort at Hogwarts.
- The Battle of Hogwarts takes place, and Voldemort is ultimately defeated by Harry, marking the end of the Second Wizarding War.