The movie begins when Harry and Dumbledore are in the Department of Mysteries, just after the events of The Order of the Phoenix where Voldemort disappears in front of the Minister, and Harry and Dumbledore are being questioned for the Daily Prophet. The flashback ends and switches to present London where Death Eaters attack Ollivander's Wand Shop in Diagon Alley abducting Ollivander himself, as well as attacking the Millennium Bridge over the River Thames.

Meanwhile, in a cafe in Surbiton station, Harry is shown flirting with a waitress, but Dumbledore arrives and tells him that it is urgent that he goes with him. They apparate into a Muggle village outside of London, and in a house that appears to have been recently attacked, they visit Horace Slughorn. It turns out that the ransacked house was merely a ruse by Slughorn to make Death Eaters believe that he was not home as they have been attempting to recruit him for more than a year. Dumbledore asks Horace to come back and teach at Hogwarts School, and Professor Slughorn reluctantly agrees. It is later revealed that Professor Slughorn has a very important memory about Tom Riddle, the boy who became Lord Voldemort. This is why Dumbledore asks him to come back to teach at Hogwarts.

The scene then cuts to Bellatrix and Narcissa Malfoy, when they visit Snape's house. It is revealed that the Dark Lord has chosen Draco Malfoy, Narcissa's son, and Bellatrix's nephew to perform a task for him. Narcissa begs Snape to look after Draco, they perform the Unbreakable Vow, where Snape has to swear that he will look after Draco, and if Draco fails the task, Snape will do it for him.

Dumbledore and Harry apparate to the Burrow, and Harry stays there for the rest of the summer with the Weasleys and Hermione. While staying at the Burrow, Harry starts to show feelings for Ginny, but then he finds out that Ginny has a boyfriend already: Dean Thomas. Also it is shown quite frequently at the Burrow that Ron and Hermione start flirting with each other. Harry also notices this.

Just before school starts, the Weasleys, Harry, and Hermione go to Diagon Alley, where they visit Fred and George's new trick shop. While there, Cormac McLaggen starts flirting with Hermione, but Hermione ignores him. Also, Lavender Brown, a fellow Hogwarts student flirts obviously with Ron. While there, Fred and George give Harry a small bit of Peruvian Darkness Powder, which he will later use on the Hogwarts Express.

After the trio leave the trick shop, they see Draco and his mother Narcissa walking into Borgin and Burkes, a Dark Magic shop (the same shop Harry arrives at when using Floo Powder in the second film). They witness many Death Eaters performing a ritual, which leads Harry to believe that Malfoy is now a Death Eater.

A few days later, Harry, Ron, and Hermione are on the train to Hogwarts. Harry uses the darkness powder from Diagon Alley within a boxcar being used by Slytherins to act as a diversion while Harry climbs on the above luggage rack to spy on Draco Malfoy. Malfoy becomes aware of Harry's presence when he sees a suitcase move by itself. When the train arrives at Hogwarts, Draco petrifies Harry and stomps on Harry in the face, breaking his nose, and leaves him on the floor under his invisibility cloak. Luna Lovegood finds him with her Spectrespecs, and together they walk to the school.

As the film progresses, Harry finds a very old Potions textbook filled with small footnotes and revisions. Harry follows these changes, which leads him to get top marks in the class, beating even Hermione. On the front page, it mysteriously says, "This book is property to the Half-Blood Prince." Meanwhile, Malfoy is seen on several occasions sneaking into the Room of Requirement trying to fix a large, mysterious cabinet. Also, Dumbledore shows Harry a memory of when he first met Tom Riddle in an Orphanage.

Close to Christmas time, the trio witnesses Katie Bell, another Gryffindor, get cursed by a necklace when she was bewitched to deliver it to Dumbledore. Harry is convinced that Malfoy cursed the necklace.

Ron and Hermione continue to get closer, but that changes when Ron tries out for the Gryffindor Quidditch team as the keeper because Oliver Wood has left. Gryffindor wins the game against Slytherin after Ron saves every Goal, and in the party afterwards, Lavender Brown kisses him passionately. Hermione sees this, and runs out of the room. Harry follows her, finding her crying in the hallway with summoned birds flying over her. Harry comforts her when she tells him that she knows that he likes Ginny, and tells him that she has feelings for Ron. She then asks him how it feels to see Ginny with Dean, and Harry says "It feels how your feeling now." Hermione continues to cry on Harry's shoulder, and to Harry's horror, Ron and Lavender walk in looking for a private place to snog. Hermione gets angry and sets the birds on Ron, and Ron runs out of the room, leaving Harry comforting the heartbroken Hermione.

Harry, Ron, and Ginny go back to the Burrow for Christmas break. One night, just before Harry and Ginny are about to kiss, Bellatrix Lestrange and Fenrir Greyback arrive in an attempt to set the burrow on fire, then flee into the field surrounding the Burrow. Harry and Ginny follows them, but the Death Eaters leave as Lupin and Tonks arrive. While leaving, Bellatrix sets the Burrow on fire as the Weasley's watch helplessly.

Back at Hogwarts, Ron and Hermione are not talking. One evening, Harry finds Ron in the dormitory, obsessively in love with Romilda Vane. Ron apparently ate some chocolate on Harry's bed, which contained a very strong love potion. Harry escorts Ron to Professor Slughorn to cure him. After Ron is cured, Slughorn offers both boys a drink, unaware that it was actually poison. Ron drinks it, then falls unconscious. Later, at the Hospital Wing, Ron is nursed back to health, and it is revealed that the poisonous drink was actually intended to be given to Dumbledore (another attempt by Malfoy). In the Great Hall, Harry talks to Katie, who apparently recovered from being cursed. He notices Malfoy leaving apprehensively, signaling that Malfoy was the person trying to kill Dumbledore. Harry follows Malfoy into the bathroom where he finds him crying. They have a duel, and Harry casts the Sectumsempra curse on him which he found in the Potions Book belonging to the "Half Blood Prince", causing huge gashes in his body. Snape heals Draco, and later Harry decides that the potion book is nothing but a cheat-sheet. He and Ginny go into the Room of Requirement to hide it. While closing his eyes so that Ginny can hide it, Ginny kisses Harry stating that "I'll hide in here forever if you like".

Harry also continues to try to get Professor Slughorn to reveal his memory, and after taking Felix Felicis (a luck potion he won earlier in a Potions competition), Harry goes down to Hagrid's hut and finds him burying Aragog, the giant spider (from the Chamber of Secrets movie). After, he talks to Professor Slughorn and successfully gets him to give Harry the memory.

The memory shows Professor Slughorn telling a young Tom Riddle about a dark piece of magic called a Horcrux. A Horcrux is a piece of someones soul that has been split away from the body and put into an object for safe keeping. So that if a person dies, they do not truly die as a piece of their soul is still alive. Dumbledore tells Harry that he believes that Voldemort split his soul into seven pieces and created 6 Horcruxes (the 7th piece being in his body) and that two are already destroyed (one being Marvolo Gaunt's ring, destroyed by Dumbledore; the other Tom Riddle's diary). And Dumbledore thinks he knows where another is.

Dumbledore and Harry apparate in a cave to find the third Horcrux. There is a giant lake with an island in the middle. After warning Harry not to disturb the surface of the water they find a boat that takes them to the island. In order to get the Horcrux they have to drink a potion that is in a bowl. Dumbledore drinks the potion, which causes him unbearable pain as its intended to weaken the seeker of the Horcrux. After Dumbledore drinks all the potion, Harry retrieves the Horcux: a locket. However Dumbledore needs water to counter the effects of the potion and the cup he has used to drink the potion wont hold water made by magic therefore he has to take water from the Lake. After filling the cup Harry is pulled into the lake by the Inferi (human corpses that are bewitched to do a Dark wizard's bidding).

Dumbledore saves him by creating many rings of fire, killing the Inferi. The two apparate back to Hogwarts, where Dumbledore tells Harry to go and find Professor Snape. Death Eaters arrive in Hogwarts after Draco managed to fix the Vanishing Cabinet inside the Room of Requirement. Draco and the Death Eaters arrive where Harry and Dumbledore apparated and Draco and tells Dumbledore that Voldemort has chosen him to kill Dumbledore, and that if he doesn't, he will die.

After talking to Draco, Dumbledore manages to begin to convince Draco that he doesn't need to kill him and that he can keep him safe, Draco begins to lower his wand. However, Snape appears and fulfills his vow to Bellatrix and Narcissa to kill Dumbledore. The Death Eaters as well as Snape attempt to escape Hogwarts; as they leave, Bellatrix sets Hagrid's hut on fire. Harry appears and tries to duel Snape, but Snape is too powerful and easily overpowers Harry.Before Snape leaves, he reveals to Harry the he is the Half-Blood Prince. Harry returns to Hogwarts to pay his respects to Dumbledore, as the staff and students of Hogwarts do the same.

The next morning Harry and Hermione discuss that the locket is a fake. They discover a note inside that says: "To the Dark Lord, I know I will be dead long before you read this, but I want you to know that it was I who discovered your secret. I have stolen the real Horcrux and intend to destroy it as soon as I can. I face death in the hope that when you meet your match, you will be mortal once more" signed by "R.A.B".

Harry then decides that he will not be returning to Hogwarts next year as he will be searching for the remaining Horcruxes, and Ron and Hermione decide that they will go with Harry. Harry Potter and the Half-Blood Prince ends with Harry, Ron, and Hermione enjoying their last day at Hogwarts as Fawkes, Dumbledore's phoenix, flies away symbolizing that Dumbledore is really dead, and that soon Harry, Ron, and Hermione must leave the safe haven that they have known for the last six years.

 

created by DILIP CHANDRA