MagiStream

Just before the start of the novel, Voldemort, the most powerful evil wizard in living memory, killed Harry's parents but mysteriously vanished after trying to kill Harry. While the wizarding world is celebrating Voldemort's downfall, Professor Dumbledore, Professor McGonagall and Hagrid place the one year-old orphan in the care of his Muggle (non-wizard) aunt and uncle, Vernon and Petunia Dursley.

For ten years, they and their son Dudley bully Harry. Shortly before Harry's eleventh birthday, a series of letters arrive, addressed to Harry but destroyed by his uncle before Harry can read them. As a result, a torrent of letters pour into the house through every opening, however small, and to escape this, Vernon Dursley takes the family to a lonely island. As they are settling in, Hagrid bursts through the door to tell Harry what the Dursleys have kept from him: Harry is a wizard and has been accepted at Hogwarts for the coming year.

Hagrid takes Harry to Diagon Alley, a magically-concealed shopping precinct in London, where Harry is bewildered to discover how famous he is among wizards as "the boy who lived." He also finds that in the wizarding world he is quite wealthy, since a bequest from his parents has remained on deposit at Gringotts Bank. Guided by Hagrid, he buys the books and equipment he needs for Hogwarts - and finds that the only wand that works well for him is effectively the twin of Voldemort's.

A month later, Harry leaves the Dursleys' home to catch the Hogwarts Express from King's Cross railway station. There he is befriended by the Weasley family, who show him how to pass through the magical wall to Platform 9 ¾, where the train is waiting. While on the train Harry makes friends with Ron Weasley, who tells him that someone tried to rob a vault at Gringotts. Another new pupil, Draco Malfoy, accompanied by his beefy but dim sidekicks Vincent Crabbe and Gregory Goyle, offers to advise Harry, but Harry dislikes Draco's arrogance and prejudices.

Before the term's first dinner in the school's Great Hall, the new pupils are allocated to houses by the magical Sorting Hat. The Hat assigns most pupils instantly, particularly when sending Draco, Crabbe and Goyle to Slytherin but telepathically discusses with Harry about whether the boy's ambition would make Slytherin the best choice for him. When Harry silently but vehemently objects, the Hat sends him to join the Weasleys in Gryffindor. While Harry is eating, Professor Snape catches his eye and Harry feels a sudden stab of pain in the scar Voldemort left on his forehead, which fades as quickly.

After a traumatic first Potions lesson with Snape, Harry and Ron visit Hagrid, who lives in a rustic house on the edge of the Forbidden Forest. There they learn that the attempted robbery at Gringotts happened the day Harry was withdrawing money, and Harry remembers Hagrid removing a small package, emptying a vault that was later broken into and searched.

During the new pupils' first flying lesson, Neville Longbottom breaks his wrist and Draco takes advantage to throw the forgetful Neville's fragile Remembrall high in the air. Harry gives chase on his broomstick, catching the Remembrall inches from the ground. Professor McGonagall dashes out and appoints him as Gryffindor's new Seeker.

Draco tricks Ron and Harry into a midnight excursion, and Neville and the bossy Hermione Granger, both also in Gryffindor, accompany the pair to keep them out of trouble. All four accidentally enter a forbidden corridor and find a room containing a huge three-headed dog. The group beats a hasty retreat, and only Hermione notices that the dog is standing over a trap-door. Harry concludes that the monster guards the package Hagrid retrieved from Gringotts.

After Ron criticizes Hermione's ostentatious proficiency in Charms, she hides in tears in the girls' toilet. Professor Quirrell reports that a troll has entered the dungeons. While everyone else returns to their dormitories, Harry and Ron rush to warn Hermione. The troll corners Hermione in the toilet but, while Harry stabs it with his wand, Ron knocks out the troll with its own club, using the levitation spell Hermione demonstrated in Charms. When a posse of professors arrives, Hermione takes the blame for the battle and becomes a firm friend of the two boys.

The evening before Harry's first Quidditch match, he sees Snape receiving medical attention from Filch for a bite by the three-headed dog. During the game, Harry's broomstick goes out of control, endangering his life, and Hermione notices that Snape is staring at Harry and muttering. She dashes over to the Professors' stand, knocking over Professor Quirrel in her haste, and sets fire to Snape's robe. Harry regains control of his broomstick and catches the Golden Snitch, winning the game for Gryffindor. Hagrid refuses to believe that Snape was responsible for Harry's danger, but lets slip that he bought the three-headed dog, and that the monster is guarding a secret that belongs to Professor Dumbledore and someone called Nicolas Flamel.
Harry and the Weasleys stay at Hogwarts for Christmas, and one of Harry's presents, from an anonymous donor, is an Invisibility Cloak. Harry uses the Cloak to search the library's Restricted Section for information about the mysterious Flamel, has to evade Snape and Filch after an enchanted book shrieks an alarm, and slips into a room containing the Mirror of Erised, which shows his parents and several of their ancestors. Harry becomes addicted to the Mirror's visions and is rescued by Professor Dumbledore, who explains that it shows what the viewer most desperately longs for.

When the rest of the pupils return for the next term, Draco plays a prank on Neville, and Harry consoles Neville with a sweet. The collectible card wrapped with the sweet identifies Flamel as an alchemist. Hermione soon finds that he is a 665-year-old man who possesses the only known Philosopher's Stone, from which can be extracted an elixir of life. A few days later Harry notices Snape sneaking towards the outskirts of the Forbidden Forest. There he half-hears a furtive conversation about the Philosopher's Stone, in which Snape asks Professor Quirrell if he has found a way past the three-headed dog and menacingly tells Quirrell to decide whose side he is on. Harry concludes that Snape is trying to steal the Stone and Quirrell has prepared a series of defences for it.

The three friends discover that Hagrid is raising a baby dragon, which is against wizard law, and arrange to smuggle it out of the country around midnight. Draco arrives, hoping to raise the alarm and get them into trouble, and Neville comes to warn them of Draco's mischief. Although Ron is bitten by the dragon and is sent to the infirmary, Harry and Hermione spirit the dragon safely away. However, they are caught, and Harry loses the Invisibility Cloak. As part of their punishment, Harry, Hermione, Draco and Neville are compelled to help Hagrid to rescue a badly-injured unicorn in the Forbidden Forest. They split into two parties, and Harry and Draco find the unicorn dead, surrounded by its blood. A hooded figure crawls to the corpse and drinks the blood, while Draco screams and flees. The hooded figure moves towards Harry, who is knocked out by an agonizing pain spreading from his scar. When Harry regains consciousness, the hooded figure has gone and a centaur, Firenze, offers to give him a ride back to the school. The centaur tells Harry that drinking a unicorn's blood will save the life of a mortally injured person, but leave them only barely alive. Firenze suggests Voldemort drank the unicorn's blood to gain enough strength to make the elixir of life from the Philosopher's Stone, and regain full health by drinking that. On his return, Harry finds that someone has slipped the Invisibility Cloak under his sheets.

A few weeks later, while relaxing after the end-of-session examinations, Harry suddenly wonders how something as illegal as a dragon's egg came into Hagrid's possession. The gamekeeper says he was given it by a hooded stranger who bought him several drinks and asked him how to get past the three-headed dog, which Hagrid admits is easy, playing music sends it to sleep. Realising that one of the Philosopher's Stone's defenses is no longer secure, Harry goes to inform Professor Dumbledore, only to find that the headmaster has just left for an important meeting. Harry concludes that Snape faked the message that called Dumbledore away and will try to steal the Stone that night.

Covered by the Invisibility Cloak, Harry and his two friends go to the three-headed dog's chamber, where
Harry sends the beast to sleep by playing a flute. After lifting the trap-door, they encounter a series of obstacles, each of which requires special skills possessed by one of the three, and one of which requires Ron to sacrifice himself. In the final room Harry, now alone, finds not Snape, but Quirrell. Quirrell admits that he let in the troll that tried to kill Hermione in the toilet, and that he tried to kill Harry during the first Quidditch match but was knocked over by Hermione. Snape had been trying to protect Harry and suspected Quirrell. Quirrell serves Voldemort and, after failing to steal the Philosopher's Stone from Gringotts, allowed his master to possess him in order to improve their chances of success. However the only other object in the room is the Mirror of Erised, and Quirrell can see no sign of the Stone. At Voldemort's bidding, Quirrel forces Harry to stand in front of the Mirror. Harry feels the Stone drop into his pocket and tries to stall. Quirrell removes his turban, revealing the face of Voldemort on the back of his head. Voldemort/Quirrell tries to grab the Stone from Harry, but simply touching Harry causes Quirrell's flesh to burn. After further struggles Harry passes out.

He awakes in the school hospital, where Professor Dumbledore tells him that he survived because his mother sacrificed her life to protect him, and Voldemort could not understand the power of such love. Voldemort left Quirrell to die, and is likely to return by some other means. Dumbledore had foreseen that the Mirror would show Voldemort/Quirrell only themselves making the elixir of life, as they wanted to use the Philosopher's Stone; Harry was able to see the Stone in the Mirror because he wanted to find it but not to use it. The Stone has now been destroyed.

Harry returns to the Dursleys for the summer holiday, but does not tell them that under-age wizards are forbidden to use magic outside Hogwarts.

Soon after the start of Harry's second year at Hogwarts, messages on the walls of the corridors say that the mythical Chamber of Secrets has been re-opened and that the "heir of Slytherin" would kill all pupils whose parents are not both magical, which includes Hermione. At intervals various inhabitants of the school are found petrified in corridors. Meanwhile, Harry, Ron, and Hermione discover Moaning Myrtle, the ghost of a girl who was killed the last time the Chamber was opened, and who now haunts the girls' toilet in which she died. Myrtle shows Harry a diary bearing the name Tom Marvolo Riddle. Although its pages are blank, it responds when Harry writes in it. Eventually the book shows him Hogwarts as it was fifty years ago. There he sees Tom Riddle, a pupil at the time, pin the blame for opening the Chamber on Rubeus Hagrid, who was then thirteen years old and already devoted to keeping dangerous magical creatures as pets.

Four months later, the diary is stolen, and shortly afterward Hermione is petrified. However, she holds a note explaining that the culprit is a basilisk, a huge serpent whose gaze kills those who look into its eyes directly but only petrifies those who look into them by means of a reflecting surface, such as water or a mirror. Hermione concluded that the monster travels through the school's pipes and emerges through the toilet Myrtle haunts. As the attacks continue, Cornelius Fudge, the Minister for Magic, holds Hagrid in the wizards' prison as a precaution. Lucius Malfoy, a former supporter of Voldemort who claims to have reformed, then announces that the school's governors have suspended Dumbledore from the position of headmaster.

After Ron's younger sister Ginny is taken into the Chamber, the staff insist that the Dark Arts teacher, Gilderoy Lockhart, should handle the situation. However, when Harry and Ron go to his office to tell him what they have discovered about the basilisk, Lockhart reveals that he is a fraud who took credit for the accomplishments of others and attempts to erase the boys' memories. Disarming Lockhart, they march him to Moaning Myrtle's toilet, where Harry opens the passage to the Chamber of Secrets. In the sewers under the school, Lockhart grabs Ron's wand and tries again to wipe the boys' memories, but Ron's wand had been damaged in an accident at the start of the school year and the spell backfires, inflicting total amnesia on Lockhart, collapsing part of the tunnel and separating Harry from Ron and Lockhart.

While Ron attempts to tunnel through the rubble, Harry enters the Chamber of Secrets, where Ginny lies beside the diary. As he examines her, Tom Riddle appears, looking exactly as he did fifty years ago, and explains that he is a memory stored in the diary. Ginny wrote in it about her adolescent hopes and fears, and Riddle won her confidence by appearing sympathetic, possessed her, and used her to open the Chamber. Riddle also reveals that he is Voldemort as a boy. He further explains that he learned from Ginny who Harry was and about his own deeds as Voldemort. When Ginny realised that she had been responsible for the attacks, she attempted to throw the diary away, which is how it came into Harry's possession. Riddle then releases the basilisk to kill Harry. Dumbledore's pet phoenix, Fawkes, brings a magnificent sword wrapped in the Sorting Hat. Harry uses the sword to kill the basilisk, but only after being bitten by the creature's venomous fangs, one of which breaks off. As Riddle gloats over the dying Harry, Fawkes cures him with its tears. Harry stabs the diary with the broken fang, and Riddle screams and vanishes. Ginny revives after Riddle's disappearance and they return to Ron, who is still watching over the amnesic Lockhart. Fawkes carries all four out of the tunnels.

Harry recounts the whole story to Dumbledore, who has been reinstated. The headmaster revokes his threat to expel the boys if they broke more rules and gives them special awards for services to the school. When Harry mentions his fears that he is similar to Tom Riddle, Dumbledore says that Harry chose Gryffindor House, and only a true member of that House could have used Godric Gryffindor's sword to kill the basilisk. Lucius Malfoy bursts in, and Harry accuses him of slipping the diary into one of Ginny's books while all the pupils were shopping for school books. Malfoy replies, "Prove it." Finally, all of the basilisk's petrified victims are revived by a potion, the preparation of which has taken several months.

The book begins when Harry flees the Dursleys' after losing his temper with Uncle Vernon's visiting sister, Aunt Marge, and inadvertently causing her to be magically inflated. He is rescued by the Knight Bus and arrives at The Leaky Cauldron, where he meets Cornelius Fudge, the Minister of Magic. Harry learns that the Aunt Marge has been rescued and he will not face any punishment, and hears news about Sirius Black, a mass-murderer who has escaped the wizarding prison Azkaban.

Harry reunites with his friends Ron Weasley and Hermione Granger. Harry also learns that he could be a target of Sirius Black. On the journey, the Hogwarts Express is searched by Dementors, dark, sinister beings that drain the happiness of anyone nearby and cause Harry to pass out.

Security has been tightened at Hogwarts, with more Dementors guarding the entrance. Two new teachers have been appointed: Remus Lupin for Defence Against the Dark Arts and Rubeus Hagrid for Care of Magical Creatures. Their first lesson with Hagrid proves disastrous after Draco Malfoy deliberately allows himself to be attacked by Buckbeak the Hippogriff. Malfoy's father later makes sure that Buckbeak is sentenced to death. Lupin explains to Harry that he is more vulnerable to the Dementors as he has seen genuine horrors in his past. After another encounter with the Dementors, this time during Quidditch, Harry persuades Lupin to teach him how to produce a Patronus Charm, a shield and guardian against the Dementors.

Despite the Dementors, Sirius Black breaks into the castle and tries to force entry to Gryffindor Tower. Fred and George Weasley show Harry a secret passageway to Hogsmeade, the local village where most students are allowed to visit on weekends. During his visit, Harry overhears that Black was a great friend of the Potters and Harry's godfather, but betrayed them to Lord Voldemort, and murdered their friend Peter Pettigrew along with 12 bystanders. At school, Black breaks in a second time and manages to get into Harry's dormitory, but flees after Ron wakes up.

Harry is nearly caught during another illegal visit to Hogsmeade, while Ron discovers that Scabbers has disappeared and believes he has been eaten by Crookshanks, causing a falling-out between him and Hermione. Scabbers is later found by Hermione in Hagrid's house when the three of them visit him just before the Hippogriff is executed. On their way back, Ron is suddenly attacked by a vicious dog and dragged into a passage beneath a highly aggressive tree, the Whomping Willow. Harry and Hermione follow him in and come into a boarded-up building called the Shrieking Shack. They discover that the dog has transformed into Sirius Black.

Harry tries to attack Black before Lupin arrives. Lupin admits to being a werewolf and that he, Black and Pettigrew were great friends with James Potter. His friends helped make his werewolf transformations enjoyable by becoming Animagi (wizards who can transform into an animal at will). Black explains that he was meant to protect the Potters but secretly switched this duty to Pettigrew as a decoy. He also did not kill Pettigrew, but Pettigrew escaped by blasting the street and turning into a rat, and they force Scabbers to reveal his true identity. Harry stops Black and Lupin from killing Pettigrew and they return to the castle. Suddenly, the full moon emerges and Lupin transforms, Pettigrew escapes and Harry and Sirius are surrounded by Dementors who attempt to perform their Kiss (destroying the soul of their victim) but they are saved at the last minute by a Patronus sent by someone who Harry believes to be his father.
Harry wakes up to learn that Black is cornered and about to face the fate worse than death, even though Dumbledore privately explains that he believes their story. Hermione uses her Time Turner (used for attending extra lessons) to take Harry back in time with her. (How exactly time-turning works is not clear. It seems that pre-time-travelling Harry first has to get past the Dementors in order to become time-travelling Harry who then can save pre-time-travelling Harry.)

Harry and Hermione rescue Buckbeak and re-watch the scenes of the night, until they see the Dementors cornering Harry and Sirius. Harry is determined to see who sent the Patronus, only to realise at the last minute that it was himself. With this knowledge, he casts a powerful Patronus which saves his past self and Sirius. Sirius is rescued and flees on Buckbeak, while Harry and Hermione return to the hospital wing of the school at the same time as they went back in time.

Snape is furious over Black's escape and is convinced that Harry, Ron and Hermione were involved, but is completely unable to prove it as neither of them appear to have strayed from the Hospital Wing ever since they arrived. The next day, Snape reveals to the school that Lupin is a werewolf, and Lupin immediately resigns. Harry is worried that Pettigrew may help Voldemort to return, but Dumbledore explains that Harry may in future be glad that he helped save Pettigrew's life. On the way back from the school, Harry receives a letter from Sirius saying that he is successfully in hiding.

The book opens with Harry Potter having a dream about Frank Bryce, the ex-caretaker at the Riddle family mansion, who is caught eavesdropping on a deformed Tom Riddle and his servant, Peter Pettigrew. In Harry's dream, Bryce is killed by Voldemort. Later in the summer, Harry, Hermione Granger, and the Weasley family take a trip to the Quidditch World Cup. While there, Death Eaters, Voldemort's servants, storm the grounds, harass some muggles, and run away when they see the Dark Mark in the sky.

Back at Hogwarts Albus Dumbledore announces during the welcoming feast that the school will host the Triwizard Tournament, an inter-school competition. One student from each of three magical schools will be chosen by the Goblet of Fire to compete. The other two magical institutions, Beauxbatons Academy, and Durmstrang Institute, arrive at Hogwarts two months into the school term. The champions chosen by the goblet were: Fleur Delacour from Beauxbatons, Viktor Krum of Durmstrang, and Cedric Diggory of Hogwarts. Mysteriously, Harry is also chosen, even though he did not submit his name, and is underage and ought to have been magically blocked from doing so. Ron Weasley is instantly infuriated, thinking Harry submitted himself, and their friendship suffers.

The new Defense Against the Dark Arts professor is Alastor "Mad-Eye" Moody, a former Auror and Dumbledore's friend. He teaches his students the three Unforgivable Curses in class, a lesson which is illegal. Those curses are the Imperius Curse, which forces the victim to do the caster's bidding; the Cruciatus Curse, a spell that tortures its victim; and the killing curse called Avada Kedavra. Harry learns he is the only known person to have survived the killing curse, cast against him by Voldemort when Harry was a baby.

In the first task of the tournament, the champions each are to retrieve a golden egg from a dragon, which contains a clue for the second task. Harry completes the task with help from Rubeus Hagrid and Professor Moody. Following the end of the first task, Ron and Harry mend their broken friendship. The second tournament task requires retrieving something important taken from each champion hidden in the Black Lake. Ten minutes before the task, Harry is given gillyweed by Dobby the house elf so he can breathe underwater. Harry finds the four “important objects" of the tournament's contestants: Ron, Hermione, Cho, and Fleur's little sister, Gabrielle Delacour. He is forced to rescue Gabrielle along with Ron when Fleur does not come, which causes him to lose the challenge, but he gain points for 'moral fibre.'

One night after the second task, Harry and Krum are startled when a disheveled Barty Crouch, Sr. emerges from the forest, mumbling nonsense and demanding to see Dumbledore. Harry runs for help, but when he returns with Dumbledore, they find Krum unconscious and Crouch missing. Harry learns more about the Crouches when he sees one of Dumbledore's memories in the Pensieve, a memory storing tool. The memory shows Barty Crouch, Jr, a Death Eater, sentenced to Azkaban by Barty Crouch Sr for torturing Frank and Alice Longbottom (Neville's parents) into insanity.

The third and final tournament task involves navigating a labyrinth located on the Quidditch Pitch which is filled with magical obstacles. Harry and Cedric successfully help each other navigate the maze. They reach the Triwizard cup and agree to take hold of it simultaneously, making both of them the winners. The Cup turns out to be a portkey that transports them to an old graveyard in Little Hangleton. Pettigrew and a deformed Lord Voldemort, are there. Pettigrew kills Diggory, and ties Harry's hands and feet to the Riddle tombstone. He then uses a bone from Voldemort's father's grave, some of Harry's blood, and his own cut-off hand in a magical ritual that restores Lord Voldemort to a new body.

Voldemort summons Death Eaters, and reveals that a servant of his at Hogwarts ensured that Harry would participate in the tournament, win it, and thus be brought to the graveyard. Harry tries to disarm Voldemort with the Expelliarmus spell, at exactly the same time as Voldemort uses the killing curse. The two curses meet and interlock, causing a bond between the wands that displays the "echoes" (described by Dumbledore) of Voldemort's most recent murdered victims, including Cedric, James Potter and Lily Potter. The "echoes" provide protection to Harry, allowing him to escape with Cedric's body and leaving Voldemort behind in a rage.

Harry, carrying Cedric's body, returns to the school grounds. Moody rushes Harry to his office, where he reveals that he was Voldemort's servant, and attempts to kill Harry himself. Moody is stopped by Dumbledore, Severus Snape, and Minerva McGonagall. Dumbledore feeds Moody Veritaserum, and they discover that "Moody" is actually Barty Crouch, Jr., who was smuggled out of Azkaban and was using a Polyjuice Potion to impersonate the real Alastor Moody. Cornelius Fudge, the Minister for Magic, arrives at Hogwarts accompanied by a dementor. When the Dementor enters the room where Crouch, Jr. stands, it swoops down and gives him the “Dementor's Kiss", sucking out his soul. Fudge refuses to believe Dumbledore's and Harry's word that Voldemort is back.

Harry is crowned Triwizard Champion and awarded with 1,000 galleons. Days later, Dumbledore then makes an announcement at the gloomy Leaving Feast, telling everybody about Voldemort and saying that to deny the true way Cedric died would be 'an insult to his memory.' While leaving the Hogwart's Express on King's Cross Station, Harry gives his winnings to Fred and George to start a joke shop and Harry sets off for another summer at the Dursleys'.

This novel begins when Harry and his cousin, Dudley, are attacked by dementors. Harry uses magic to fight them off, and must attend a disciplinary hearing for it. In response to Voldemort's reappearance, Dumbledore re-activates the Order of the Phoenix, a secret society which works to defeat Voldemort's minions and protect Voldemort's targets, including Harry. Despite Harry's description of Voldemort's recent activities, the Ministry of Magic and many others in the magical world refuse to believe that Voldemort has returned.

In an attempt to enforce its version of school curriculum, the Ministry appoints Dolores Umbridge as the new High Inquisitor of Hogwarts. She transforms the school into a quasi-dictatorial regime and refuses to allow the students to learn ways to defend themselves against dark magic. Harry forms a secret study group and begins to teach his classmates the higher-level skills he has learned. The novel introduces Harry to Luna Lovegood, an airy young witch with a tendency to believe in oddball conspiracy theories. Moreover, it reveals an important prophecy concerning Harry and Voldemort. Harry also discovers that he and Voldemort have a telepathic connection, allowing Harry to view some of Voldemort's actions. In the novel's climax, Harry and his school friends face off against Voldemort's Death Eaters. The timely arrival of members of the Order of the Phoenix saves the children's lives, but Sirius Black, Harry's godfather, is murdered by Bellatrix Lestrange. Many Death Eaters are captured and, most importantly, the return of Voldemort is confirmed within the magical world.

Harry Potter accompanies Albus Dumbledore on a trip to persuade retired Hogwarts professor Horace Slughorn to return to teaching, before arriving at The Burrow.

At Hogwarts, Severus Snape is named the new Defence Against the Dark Arts instructor, with Slughorn becoming the Potions teacher. Harry and Ron are able to enrol in his class, but Harry's borrowed book has notes and corrections that yield better results than the textbook's instructions, winning him a vial of Felix Felicis, a luck potion, on his first day in class. The book formerly belonged to "The Half-Blood Prince".
Harry becomes suspicious of his rival Draco Malfoy, after overhearing several of his conversations, and when Katie Bell is almost killed while attempting to deliver a cursed necklace under the influence of the Imperius Curse. Meanwhile, Ron is displeased with his younger sister Ginny dating anybody, forcing Harry to ignore his attraction. After an argument with Ginny in which Ron's dating inexperience is made clear, Ron takes up with Lavender Brown, creating a divide between him and Hermione. This rift is only mended when he accidentally consumes a love potion attracting him to Romilda Vane, and then poisoned mead which almost kills him.

Dumbledore privately tutors Harry, using his Pensieve to show Harry memories of Voldemort's past. Dumbledore asks Harry to retrieve a key memory from Slughorn regarding Slughorn's conversation with a sixteen-year-old Tom Riddle. Harry uses some of his Felix Felicis to acquire the memory.

The memories reveal that Voldemort splintered his soul into six fragments attached to objects called Horcruxes, while leaving a seventh piece in his body, in order to achieve immortality. As long as any of the Horcruxes exists Voldemort cannot be killed. Two Horcruxes have been destroyed - Tom Riddle's diary, by Harry in the Chamber of Secrets four years earlier; and Marvolo Gaunt's ring, by Dumbledore during the summer before this school year. Three of the remaining Horcruxes are a locket formerly owned by Salazar Slytherin, a cup formerly owned by Helga Hufflepuff, and the snake Nagini. Dumbledore speculates that the sixth unidentified Horcrux may be something associated with Gryffindor or Ravenclaw, as Riddle would have wanted something from each of the houses of Hogwarts, which he regarded as his home.

After seeing Harry cast an unusual curse, "Sectumsempra" (a dark curse which leaves deep gashes) against Draco Malfoy, Snape attempts to confiscate the Half-Blood Prince's Potions book, but Harry gives him Ron's copy instead and hides his copy in the Room of Requirement. Harry gets detention from Snape and misses the Quidditch finals, but Gryffindor wins the Cup. During the victory celebration Harry spontaneously kisses Ginny, and with Ron's grudging approval they begin dating.

Dumbledore locates another Horcrux and asks Harry to accompany him to destroy it. They travel to a cave and retrieve a locket, but Dumbledore is weakened after drinking a potion to obtain the Horcrux. Harry then successfully apparates to Hogsmeade with Dumbledore. After they return to Hogsmeade, they see the Dark Mark over the Astronomy Tower at Hogwarts and hurry back to the school. Dumbledore and an invisible Harry are confronted atop the tower by Draco Malfoy. Draco admits that he was behind two attacks on Hogwarts students, with both objects intended for Dumbledore, whom Voldemort had ordered Draco to kill. Dumbledore offers Draco protection from the Death Eaters, and Draco cannot bring himself to kill Dumbledore, even with the urging of fellow Death Eaters once they arrive. Instead, Snape kills Dumbledore. Harry, enraged and freed from immobility by Dumbledore's death, pursues Snape, who reveals that he is the Half-Blood Prince and fends off Harry's attacks (and Buckbeak who joins in to help Harry) until he gets outside Hogwarts grounds and Disapparates.

Harry recovers the locket from Dumbledore's body, only to discover it is a fake left by someone with the initials R. A. B., who stole the real Horcrux and left a note about his opposition to Voldemort. McGonagall tries to question Harry about what he was doing with Dumbledore and he refuses to say. McGonagall calls a meeting of the Heads of House (with Slughorn taking Snape's spot) to decide what to do. They decide to close the school, but at Harry's suggestion, agree to wait until Dumbledore's funeral so the students can say goodbye. Harry and Ginny break up because he thinks that Voldemort will use Ginny to defeat him. The Minister arrives and McGonagall lets Harry leave so he can avoid the Minister. The school year ends with Dumbledore's funeral. He and his wand are buried in a tomb beside the lake on Hogwarts's grounds. Harry vows not to return to school but to hunt for the remaining Horcruxes instead. Harry breaks up with Ginny to keep her safe from danger during his quest, and Hermione and Ron pledge him to let them accompany him.

Following Dumbledore's death, Voldemort has completed his ascension to power and gains control of the Ministry of Magic. Harry, Ron, and Hermione drop out of school so that they can find and destroy Voldemort's remaining three Horcruxes. They isolate themselves to ensure the safety of their family and friends. They do not have much knowledge about the remaining Horcruxes except the possibility that two of them are objects that belonged to Hogwarts founders Rowena Ravenclaw and Helga Hufflepuff, and that the third is Nagini, Voldemort's snake familiar. The locations of the two founders' objects are unknown, and Nagini is presumed to be with Voldemort himself. As they search for the Horcruxes, the trio learn details about Dumbledore's past, as well as Snape's true motives.

The trio recovers the first of Voldemort's Horcruxes, Salazar Slytherin's locket, by infiltrating the Ministry of Magic. They recover the Sword of Godric Gryffindor; it is one of a few objects that can be used to destroy Horcruxes, and they use it to destroy the locket. In their travels the trio come across a strange symbol, which an eccentric wizard named Xenophilius Lovegood tells them represents the mythical Deathly Hallows. The Hallows are revealed to be three sacred objects: the Resurrection Stone, a stone with the power to bring others back to life; the Elder Wand, an unbeatable wand; and an infallible Invisibility Cloak. Harry learns that Voldemort is after the Elder Wand, but the trio decides that discovering Voldemort's Horcruxes is more important than procuring the wand for themselves. They break into Bellatrix Lestrange's vault at the Wizarding Bank Gringotts to recover another Horcrux, the cup of Helga Hufflepuff. Harry learns that another Horcrux is hidden in Hogwarts, and Harry, Ron, and Hermione enter the school. They find this Horcrux, the Diadem of Ravenclaw, and successfully destroy both.

The book culminates in the Battle of Hogwarts. Harry, Ron, and Hermione, in conjunction with students and members of the wizarding world opposed to the rise of Voldemort, defend Hogwarts from Voldemort, his Death Eaters, and various magical creatures. Several major characters are killed in the first wave of the battle. Harry discovers that Voldemort inadvertently made Harry a Horcrux when he attacked him as a baby, and that he would have to die to destroy Voldemort. Harry surrenders himself to Voldemort, who attacks Harry with the Killing Curse, sending Harry to a sort of Limbo between life and death. There, Harry meets Dumbledore who explains that because Voldemort used Harry's blood to regain his full strength, Harry is protected from any harm that Voldemort could commit, meaning that the Horcrux inside of Harry is destroyed but that he can return to his body despite being hit by the Killing Curse. Harry then returns to his body, the battle resumes, and after the last remaining Horcrux destroyed, Harry is able to defeat Voldemort.