Harry Potter and the Half-Blood Prince (2009): Cast, Plot and Ending Explained

Harry Potter and the Half-Blood Prince (2009), directed by David Yates, follows Harry's sixth year at Hogwarts as Lord Voldemort's power grows and the danger spreads from the wizarding world into the Muggle world. The film opens with Death Eaters attacking London, and Draco Malfoy is handed a secret task at the school.

Dumbledore brings Harry along to persuade his old colleague Horace Slughorn to return to Hogwarts as a teacher, because Dumbledore believes Slughorn holds a memory that is key to understanding Voldemort's past. Back at school, Harry finds an old potions textbook full of handwritten notes signed by the Half-Blood Prince. Meanwhile Draco begins acting secretively, and Harry becomes convinced he is up to something dark.

If you are placing the film in the saga, it follows Harry Potter and the Order of the Phoenix, where the Ministry of Magic denied that Voldemort had returned. For the wider run of films, see Harry Potter movies in order.

The full plot of Harry Potter and the Half-Blood Prince runs from Draco's secret mission to Dumbledore's death, and the Half-Blood Prince turns out to be Severus Snape. Everything below reveals the ending.

After the London attack, Snape promises Draco's mother that he will protect her son. Harry starts his sixth year, and the Half-Blood Prince's notes make him a star in Slughorn's potions class. Dumbledore asks Harry to coax the hidden memory out of Slughorn, and Harry wins his trust with the help of a luck potion.

Romance grows between Harry and Ginny Weasley, while Ron enjoys a short, awkward relationship with Lavender Brown and Hermione feels hurt. Harry is sure Draco is plotting something, so he follows him, then wounds him badly with an unknown spell from the borrowed book.

The memory Slughorn finally gives up shows that Voldemort split his soul into Horcruxes to make himself hard to kill. Dumbledore takes Harry to a sea cave to retrieve one, and he weakens himself by drinking a painful potion that guards it. They get the locket back to the surface, but it turns out to be a fake.

Back at Hogwarts, Death Eaters have entered the school through a magical cabinet that Draco repaired. Draco corners the weakened Dumbledore but cannot bring himself to kill him. Snape arrives and kills Dumbledore, and he is then revealed as the Half-Blood Prince. Harry chases Snape but is beaten, and the school mourns its headmaster.

Harry Potter and the Half-Blood Prince opened in the US, the UK and Australia on July 15, 2009, according to The Numbers and TMDB. A verified premiere city and venue are not published in the studio or trade coverage for this film.

The opening day was not the first plan. Warner Bros. originally scheduled the film for November 21, 2008, then moved it to July 17, 2009, with Alan Horn citing the need for a mid-summer tentpole and the aftermath of the writers' strike. He also said production was not affected, according to Screen Daily. The delay meant the sixth film arrived in the summer, where Harry Potter and the Order of the Phoenix had also opened two years earlier.

In the UK the film carries a 12A certificate and in Australia an M rating, while the US rating is PG. For the full run of release dates across the saga, see Harry Potter movies in order.

The ending of Harry Potter and the Half-Blood Prince shows Snape killing Dumbledore, revealing Snape as the Half-Blood Prince, and sending Harry off to hunt the remaining Horcruxes. Spoilers follow.

Why does Snape do it? The film plants an answer early. Snape promises Draco's mother that he will protect her son, and when Draco cannot bring himself to kill the weakened Dumbledore, Snape arrives and kills Dumbledore instead. In my opinion, that is the cleanest reading the film itself supports: Snape acts so that Draco does not have to. It could be argued that the film leaves Snape's deeper loyalty deliberately open, and the later films, rather than this one, are where that question gets worked out.

Who is the actual Half-Blood Prince? It is Snape. The potions book that made Harry a star in Slughorn's class carried his handwritten notes, which is why the revelation lands after the death rather than before it. Harry spends the film trusting an anonymous author, and the film's last act punishes that trust.

The locket matters too. Harry and Dumbledore pay a heavy price in the sea cave, and the Horcrux they carry out turns out to be a fake left by someone with the initials R.A.B. That leaves the Horcrux hunt with nothing gained, only a name to chase.

What does Harry do next? After the funeral he decides not to return to school and to hunt the remaining Horcruxes, and Ron and Hermione promise to go with him. This sets up Harry Potter and the Deathly Hallows Part 1, which opens with Snape reporting to Voldemort and the Order moving Harry, and then Part 2.

One structural point I would make: this film ends on mourning and a decision. It is a quieter finish, and I think a deliberate one, because the film is spent mostly on memories, a potions book and a repaired cabinet rather than on set pieces.

Studio and trade coverage does not give a verified list of real filming sites for Harry Potter and the Half-Blood Prince, so the places below are story settings rather than confirmed shoot locations.

The film moves between three kinds of space. The opening Death Eater attack takes place in London, which carries the idea that the danger has spread from the wizarding world into the Muggle world. Most of the story then plays out at Hogwarts, in Slughorn's potions classroom, the corridors where Harry follows Draco, and the tower where Dumbledore dies. The darkest sequence is the sea cave, where Dumbledore drinks the guarding potion to reach the locket.

The look of all three came from cinematographer Bruno Delbonnel, who is credited on the film by Box Office Mojo. If you want to compare how the school and its surroundings are presented across the saga, the Harry Potter timeline places this film as the sixth of the eight main entries.

The budget of Harry Potter and the Half-Blood Prince was $250 million, the highest of any film in the Harry Potter saga and its Fantastic Beasts spin-offs, according to The Numbers. Against that, the film earned about $926 million worldwide, with $303 million domestically and $623 million internationally.

The release date moved. Warner Bros. shifted the film from its November 21, 2008 date to July 17, 2009, with Alan Horn citing the need for a mid-summer tentpole and the aftermath of the writers' strike, and saying production was not affected (Screen Daily). The Numbers lists the US release as July 15, 2009.

The film was released in 3-D post-production conversion and IMAX DMR formats, and The Numbers lists a limited re-release on September 2, 2018.

Is it the least liked film in the series? That is a matter of taste. On worldwide gross, the lowest of the eight main films is Harry Potter and the Prisoner of Azkaban at about $812 million, so the Half-Blood Prince sits fifth of the eight. For our own placement, see Harry Potter movies ranked and the Harry Potter box office page.