Harry Potter and Albus Dumbledore's private lessons

"I spend time with Harry because I have things to discuss with him, information I must give him before it is too late."

- Dumbledore explains their lessons to Severus Snape.

These private lessons took place during the course of Harry Potter's sixth year in 1996-1997 between him and the Headmaster of Hogwarts School of Witchcraft and Wizardry, Albus Dumbledore. The purpose of these lessons were to teach Harry about Lord Voldemort's past in an attempt to figure out how to defeat him, further discuss the prophecy that caused Harry's destiny, and unriddle an important secret of Voldemort's, guessed at by Dumbledore, that possibly involves Voldemort being immortal. The answers to these questions and mysteries were attempted to be found using the Pensieve, a memory-storing device in which Dumbledore and Harry could delve into memories (sometimes of the Headmaster himself and sometimes belonging to others) that would help unravel the secrets involving Voldemort, his birth, his rise to power, and his weaknesses.

First lesson
The first lesson took place at 8 p.m. on a Saturday in early September 1996. The password to Dumbledore's office was Acid Pops.

Bob Ogden's memory


In this first memory, Harry witnessed an encounter between Bob Ogden, an employee of the Department of Magical Law Enforcement, and the pure-blood House of Gaunt. Ogden, as head of the Magical Law Enforcement Patrol, was sent to the Gaunt shack to summon Morfin Gaunt to a hearing for using magic against a Muggle. The Muggle in question, Tom Riddle Sr., was attacked by Morfin by means of an unidentified jinx or hex that gave him painful hives.



Ogden was not received well by the Gaunts, who conversed with each other in Parseltongue, and Morfin ended up sending a spell that made yellow goo come from Ogden's nose, and Morfin's father, Marvolo Gaunt physically and verbally abused his daughter Merope Gaunt while brandishing Slytherin family heirlooms, a ring and his locket at Ogden. At that moment, Tom Riddle Sr. and his girlfriend, Cecilia, drove by and scoffed at the Gaunt shack, and Morfin revealed that his sister was in love with the Muggle, Tom Riddle Sr.

Marvolo Gaunt, a pure-blood supremacist and a fanatic for his Slytherin family heritage, was furious that his daughter would love a Muggle, and Ogden stopped him from throttling Merope with a Revulsion Jinx. Ogden ran from the shack into Tom and Cecilia's carriage, and after orienting himself from the collision, he Apparated. Dumbledore and Harry exited the memory, with Dumbledore then revealing that Ogden came back with reinforcements from the Ministry who overpowered Morfin and Marvolo and sent them to Azkaban, albeit with Morfin's sentence longer than Marvolo's.

Discussion
"I believe that Merope, who was deeply in love with her husband, could not bear to continue enslaving him by magical means... Perhaps she thought he would stay for the baby's sake. If so, she was wrong on both counts. He left her, never saw her again, and never troubled to discover what became of his son"

- Albus Dumbledore explaining Merope and Tom Riddle Sr.'s tragic relationship

After seeing the memory, Dumbledore explained to Harry that Marvolo Gaunt was Voldemort's grandfather and namesake for his middle name, and Merope was his mother, thus making Morfin his uncle, who he would encounter later. Tom Riddle Sr. was Voldemort's Muggle father and namesake. This memory also saw the introduced of Salazar Slytherin's Locket, an heirloom marking the familial link of the Gaunts to Salazar Slytherin, and Marvolo Gaunt's Ring, the familial link of Gaunts to the Peverells, both of which would later become some of Voldemort's Horcruxes.

This memory also introduced the Resurrection Stone as the black stone within the ring, though this would not be realised by Harry until much later. Dumbledore and Harry talked about Merope's use of a Love Potion to seduce Tom Riddle Sr., but because of her deep love for him she chose to take him off the Potion, thinking or perhaps hoping that the effects of the potion would be permanent. She was incorrect, and Riddle abandoned his wife and unborn child. Dumbledore then told Harry he should only confide in Ron Weasley and Hermione Granger about what they talked about in the lessons.

Second lesson
The second lesson took place at 8pm on a Monday in mid-October 1996.

Albus Dumbledore's memory (#1)
During this lesson, Harry witnessed Albus Dumbledore's first meeting with the eleven-year old Tom Marvolo Riddle. Dumbledore arrived at Wool's Orphanage with an appointment to speak with Mrs. Cole. While talking to Mrs. Cole, she revealed some of the incidents that have happened with Tom over the years, including the circumstances in which he was brought to the orphanage and "funny things" he has done to the other children. Dumbledore meets Tom, who is at first wary that Dumbledore is someone from the asylum, that Mrs. Cole and the others want him locked up. By lighting Tom's wardrobe on fire and forcing him to return the trinkets he stole from other children (undoubtedly by misusing his magical abilities), Dumbledore proved to Riddle that he (Dumbledore) was a wizard and convinced him to come to Hogwarts.

Dumbledore offered to help Tom in Diagon Alley and buying school books, but Tom assured him he could manage alone, and so Dumbledore informed him that the Hogwarts Express would leave from King's Cross Station on 1 September. Riddle informed Dumbledore, as the man turned to leave, that he had the rare gift of speaking to snakes, which Dumbledore told him was unusual but not unheard of.

Discussion
Before seeing the memory, Harry and Dumbledore discussed Merope's refusal to use magic any longer, the sale of the locket to Borgin and Burkes, and her death shortly after giving birth. It was revealed that Voldemort had an uncommonly powerful control of magic at such a young age, a cruel and controlling nature, and had a preference for acting alone and without a desire for friendship. When Dumbledore mentioned that the barman of the Leaky Cauldron was also named Tom, Voldemort visibly showed his contempt for anything that tied him to other people, anything that made him ordinary. Riddle wished to be different from others, separate and notorious. Thus, he soon shed the ordinary name of "Tom" and created the alias "Lord Voldemort".

The memory showed that Tom Riddle was already highly self-sufficient, secretive, and preferred to operate alone. This foreshadowed the adult Voldemort; while many Death Eaters claimed that they were in his confidence and were close to him, Voldemort never had one friend nor did he ever want one. The third important quality of this memory was Voldemort's tendency to collect trophies, such as the box of stolen articles he had hidden in his room. Many of them were taken from victims of his bullying, souvenirs from magic used against them. This magpie-like tendency was important later when Dumbledore and Harry began to unravel the secret of Voldemort's Horcruxes as it gave them an idea of the type of objects Voldemort might use to contain parts of his soul.

Third lesson
The third lesson took place at 8pm one evening in early January 1997.

Morfin Gaunt's memory
"I was very lucky to collect this, as you will undoubtedly understand when we have experienced it. Shall we?"

- Dumbledore invites Harry to witness this memory in the Pensieve

For this lesson, Dumbledore and Harry delved into the memory of Morfin Gaunt, Voldemort's uncle. The scene in question was when the sixteen-year old Tom Riddle encountered Morfin as he sought out his heritage. The memory showed that, in the absence of Merope, the Gaunt shack had gone to seed. Riddle entered the house, and because he so resembled his father, Morfin mistook him for a moment as his hated, Muggle brother-in-law. Riddle proved to Morfin that he spoke Parseltongue, and Morfin informed Riddle that Marvolo was dead and told Riddle the story of Riddle Sr. leaving Merope and Merope subsequently robbing them of Slytherin's locket. Tom Riddle, learning that in fact his father, a Muggle, left his mother, was furious, and as Voldemort moved forward, the memory ended.

Discussion
"Whatever Morfin was, he did not deserve to die as he did, blamed for the murders he had not committed."

- Albus Dumbledore on Morfin's fate

Dumbledore informed Harry that the reason the memory went dark was because Morfin could not remember anything from that point onwards. When Morfin woke up, he was alone and the ring was stolen. In Little Hangleton, the murders of Tom Riddle Sr. and his parents were revealed, and the Ministry suspected a Muggle-hater who lived across the valley from the Riddle House: Morfin. When they found him, he admitted to the murders immediately, giving details and being boastful about his deed. Upon handing over his wand, it was shown that its last spell was the Killing Curse on the Riddles. He was led to Azkaban without a fight and died there, forever lamenting the loss of the ring. Before Morfin died, however, Dumbledore visited him and used skilled Legilimency to extract the true memory, but Morfin passed away before Dumbledore could give this proof to the Ministry.

Before seeing this memory, Dumbledore explained to Harry about Tom Riddle's school years as a brilliant, handsome, quiet boy thirsty for knowledge who attracted sympathy from all the staff, which was helped through his careful flattery of them. However, Dumbledore alone did not take for granted that he was trustworthy, and Riddle was always very guarded with Dumbledore. As such, he had the sense never to charm Dumbledore as he did the other teachers. While at school, Riddle also put together a group of students whose wrongdoing would never be traced to them; the forerunners of the Death Eaters.

Harry also learned that Voldemort was obsessed with his heritage. This memory revealed how Voldemort learned the truth about his mother and father, and his own status as a half-blood, as well as that he Stunned his uncle, took his wand, proceeded to the Riddle house, and murdered his father, as well as his paternal grandparents to obliterate the Riddle line and get revenge on the father who never wanted him. He returned to the Gaunt shack, performed a False Memory Charm on his uncle, laid Morfin's wand beside its unconscious owner, grabbed the ring, and left. Dumbledore also informed Harry that, while Voldemort was underage at the time and the Ministry detected underage magic, the Ministry could only detect the magic, not the perpetrator. They were unable to tell if a child performed underage magic in a house in which witches and wizards performed magic, and thus relied on the witch and wizard parents to enforce the obedience of the child. This, as demonstrated through this memory, was not a very good system, as it allowed Voldemort to kill and frame his uncle without the Ministry attributing it to himself.

Horace Slughorn's memory (fake)
"...the most important [memory] I have collected."

- Albus Dumbledore

In this lesson, Harry witnessed Tom Riddle during his school years question Horace Slughorn. The scene began with Tom Riddle and his gang of students in Slughorn's office, being handsome and relaxed as always. Tom asked Slughorn whether or not Galatea Merrythought was retiring, and Slughorn began saying that what with Tom's ability to know things he shouldn't and his careful flattery about the people who matter and thanks Tom for the crystallized pineapple. Before he can finish his statement, the room filled with a thick white fog and Slughorn's voice, unnaturally loudly, said "You'll go wrong, boy, mark my words."

The fog cleared, and the subjects in the memory did not appear to have any idea that anything odd had happened. As it was late, Slughorn dismissed his group of students. Tom, however, lingered behind, and then asked Slughorn what the professor knew about Horcruxes. Just then, the dense fog filled the room once more and the loud voice of Slughorn boomed out once again, admonishing Tom by saying that he didn't know anything about Horcruxes, he wouldn't tell him if he did, and told him to never let the professor catch him mentioning them again.

Discussion
"This memory is everything... without it we are blind. Without it, we leave the fate of our world to chance. You have no choice. You must not fail."

- Dumbledore assigning Harry the task of retrieving the lesson. Albus Dumbledore informed Harry that key parts of the memory had been omitted, as the memory had obviously been tampered with. He told Harry that he believed Slughorn to be ashamed of what he remembered, and thus tried to rework the memory to show himself in a better light by crudely obliterating the parts Slughorn didn't want Dumbledore to see. Then, Dumbledore gave Harry the task of persuading Professor Slughorn to divulge the real memory, which Dumbledore believed was the most important piece of information of all. Dumbledore told Harry that Slughorn was an able wizard who undoubtedly carried an antidote to Veritaserum after Dumbledore got the fake memory, and was a much more skilled Occlumens than Morfin Gaunt. Thus, Dumbledore said that it would be something unique about Harry that would play to Slughorn's weaknesses and get him to hand over the true memory.

Fourth lesson
The fourth lesson took place at 8pm on a Monday in mid March 1997. The password to Dumbledore's office was Toffee Eclairs.

Hokey's memory
"Can you keep a secret, Tom? Will you promise you won't tell Mr. Burke I've got it? He'd never let me rest if he knew I'd shown it to you, and I'm not selling, not to Burke, not to anyone!"

- Hepzibah Smith prior to showing Tom Riddle Hufflepuff's cup and Slytherin's locket For this lesson, he and Dumbledore delved into the memory of Hokey, an elderly house-elf. In this memory, Tom Riddle, now an employee of Borgin and Burkes after finishing his education, paid a visit to an elderly, immensely fat, vain witch named Hepzibah Smith and her house-elf, Hokey.

Hepzibah, who enjoyed being doted on and charmed by the handsome Tom Riddle, decided to show Tom two of her most prized possessions. She first showed him Helga Hufflepuff's cup, a relic of Hogwarts founder Helga Hufflepuff. Tom showed obvious interest in the object, though did not object as it was taken away and Hokey obediently brought another treasure Hepzibah wanted to show him: Salazar Slytherin's locket.

Hepzibah revealed that she bought it from Mr. Burke for a hefty sum, who bought it from a "ragged-looking woman who seemed to have stolen it, but had no idea of its true value". Voldemort's eyes momentarily flashed scarlet, as he knew that the woman was his mother and that the locket was his birthright. Hepzibah took the locket back, and her foolish smile faltered for a moment when she momentarily glimpsed the red gleam of Voldemort's eyes. She then ordered Hokey to take the two objects away and lock them up again with the usual enchantments.

Discussion


At the beginning of this lesson, Harry was very ashamed that he was unable to procure the true memory from Slughorn, especially when Dumbledore made it clear how important that memory was. While Dumbledore did not scold him openly, he was disappointed, and Harry assured Dumbledore that he would work harder in procuring the memory.

Before going into Hokey's memory, Dumbledore explained that Voldemort reached his seventh year with top grades in every examination, and everyone expected spectacular things from Riddle, the prefect, Head Boy, etc. Despite offers, particularly from Professor Slughorn, to get him involved with the Ministry of Magic, Riddle ended up working at Borgin and Burkes, though he had previously asked the Headmaster, Armando Dippet, if he could work as the Defence Against the Dark Arts professor. According to Dumbledore, Riddle's reasoning in wanting to return to Hogwarts was because it was the first and only place he had felt at home; he may have wanted to unravel more mysteries of the ancient castle and explore magic and secrets in it never before seen by students; and to have influence over young witches and wizards so as to have a recruiting ground, a place to build up his army. Dippet said Riddle was too young at 18 and told him he could reapply in a few years. Instead, at Borgin and Burkes, he was sent to persuade people to part with their treasures for sale by the partners.

After seeing the memory, Dumbledore informed Harry that Hepzibah died two days after that scene, and Hokey was convicted of poisoning her mistress's cocoa by accident. Similar to the murder of the Riddle family and Morfin's confession, Hokey had a clear memory of putting a lethal, little-known poison in the cocoa instead of sugar, and being old and confused she didn't mean to do it. In truth, Voldemort modified her memory the same way he did to Morfin, and the Ministry was already predisposed to suspect Hokey because she was a house-elf. Soon after Hokey's conviction, Hepzibah's family discovered that her two greatest treasures were missing; in the same way, the young assistant at Borgin and Burkes vanished and no one saw Tom Riddle again for a long time.

Albus Dumbledore's memory (#2)


In this memory, Harry witnessed the man who began openly calling himself Voldemort as he returned to Hogwarts with the intention of taking up a teaching position. Voldemort entered the Headmaster's office and met with Dumbledore, who offered him a drink. They discussed how both Voldemort and Dumbledore never desired a career in the Ministry, and Dumbledore made it clear, very pleasantly, to Voldemot that he will always call him "Tom", despite the new name he has acquired. Voldemort revealed that he had returned to the school to pursue the teaching career he asked Professor Dippet about so long ago. Voldemort explained that he had done and seen much since leaving Hogwarts, and that he could share his experiences with young minds, that he had pushed the boundaries of magic further than they had ever been pushed.

Dumbledore contended that Voldemort still remained ignorant of the power of the love in magic, to which Voldemort disputed, but said that he wished to teach and that his talents were at Dumbledore's disposal. Dumbledore then surprised Voldemort with his knowledge that he would find a group of Voldemort's Death Eaters in the Hog's Head waiting for their leader to return. Dumbledore then decided to speak openly with Tom, asking him why he came to Hogwarts, surrounded by henchmen, to ask for a job he didn't want. When Tom disagreed, Dumbledore made it clear he knew Voldemort wished to return to Hogwarts, but not to teach, and asked what Voldemort's true purpose was in returning to the school. Furious, Voldemort left Dumbledore's office.

Discussion
This memory showed that Voldemort, even after his time at Borgin and Burkes, still intended to gain influence over young wizards and witches, as he continued to build his power. In the amount of time since 18-year-old Voldemort, it was clear that he had spent years learning and discovering new types of Dark magic, and mutilating his soul. Rather than teach, Voldemort may have wanted to return to Hogwarts for the reasons he wanted to when he was 18: his fondness for the place and his desire to continue studying its secrets. As well as this, however, he was also interested in obtaining more artefacts of the Hogwarts founders.

The dispute between Voldemort and Dumbledore about love was one that was very important later, as Dumbledore had always believed Voldemort to be woefully ignorant about some forms of magic, whereas Voldemort believed nothing he had learned proved Dumbledore's theory that love was powerful. Dumbledore also explained that Voldemort was still after the Defence Against the Dark Arts position, even though he didn't mention it specifically. After Dumbledore refused to give him the job, Voldemort placed a curse on the post making it so a teacher would never last more than one year.

Although this was not realised until later, Voldemort's true reason for returning to the school was to place Rowena Ravenclaw's Diadem, now a Horcrux of his, in the Room of Requirement. Voldemort had discovered the location of the diadem forest in Albania from information given to him by the Grey Lady, and he believed that the Horcrux would be safe in the Room of Requirement because he was arrogant enough to think that only he had plumbed the deepest depths and secrets of Hogwarts Castle. After his defeat during his attack at Godric's Hollow at the hands of baby Harry Potter, he later returned to the secluded forests of Albania to bide time until his return to power.

Final lesson
The final lesson took place shortly after midnight on 22 April, 1997. The password to Dumbledore's office was still Toffee Eclairs.

Background


Harry's assignment from Dumbledore was to persuade Horace Slughorn to divulge the true memory. After a few unsuccessful attempts, Harry realised what he needed to get Slughorn to give him the memory was luck; and Harry had previously won a bottle of Felix Felicis (a luck potion) from Slughorn in a Potions class. He drank some, and the potion guided him to Rubeus Hagrid's cabin, where the half-giant was holding Aragog's funeral. Slughorn accompanied Harry down to the funeral (mostly for the chance to collect valuable Acromantula venom), and Slughorn and Hagrid drank heavily, inside the hut.

Being helped by the lucky potion, Harry talked to Slughorn about the way his parents had died, how James had stood in front of Voldemort, who murdered him and then stepped over the body toward Lily. Slughorn told Harry that he had heard enough, and Harry told Slughorn that if the professor truly cared about Lily, he would help her son by giving him the memory. Slughorn was reluctant, his eyes brimming with tears, horrified at showing what he told Tom Riddle all those years ago. Harry told Slughorn that the only way they would be able to defeat Voldemort, defeat the man who killed Lily, was by having the information contained in Slughorn's memory. Slughorn then gave Harry the memory.

Horace Slughorn's memory (real)


Harry took the memory to Dumbledore, and the two of them went into the Pensieve to witness it. Harry landed in Slughorn's office many years ago, with Tom Riddle in the midst of his gang. However, unlike the fake memory, white fog did not obscure the scene after Tom asked if Professor Merrythought was retiring; instead, Slughorn winked and told Tom that he expected him to rise to Minister for Magic within twenty years, fifteen if Tom continued sending Slughorn is favourite crystallised pineapple. When the clock chimed eleven o' clock, Slughorn dismissed the students, but Tom lingered behind and asked the Professor if he knew anything about Horcruxes.

Though Slughorn seemed hesitant, he decided a brief overview of the term wouldn't hurt. Thanks to Tom's careful flattery, Slughorn revealed to him that Horcrux was the term for an object in which a person has concealed part of their soul, and that one ripped the soul apart by committing murder and then hiding the piece of soul in the preferred object; thus, the person was protected should their body be destroyed because they had pieces of their soul hidden safely elsewhere. In other words, they were immortal. Tom was particularly interested in whether one could only split their soul once, and whether splitting it into seven, the most magically powerful number, would be better than just one. Slughorn was horrified at the idea of killing seven people. Riddle then assured Slughorn that he wouldn't tell anyone what the Professor told him.

Discussion
Dumbledore told Harry that the memory had confirmed the theory which Dumbledore had been working on, but that it also confirmed that there was still a long way to go. Harry understood that the reason Voldemort didn't die when he attacked him was that Voldemort had a Horcrux (or Horcruxes) safe. Dumbledore then revealed that Harry himself handed Dumbledore proof of Horcruxes in his second year: Tom Riddle's diary. Dumbledore explained to Harry that, while it was clear Voldemort had wanted Slytherin's Chamber of Secrets to be opened once more, he was being careless about a fragment of his soul by simply passing it on to a Hogwarts student: the point of a Horcrux was to keep it well-hidden.



The Horcrux was destroyed by Harry, and Dumbledore inferred that the careless way Voldemort treated the diary meant that he had more -- or was planning to make more -- Horcruxes somewhere. Dumbledore explained when Voldemort said "I, who have gone further than anybody along the path that leads to immortality" to his gathered Death Eaters after his rebirth was referring to his Horcruxes, and that Voldemort's transformation into a less and less human state was due to him mutilating his soul. Harry mentioned that the seven Horcruxes could be anything, anywhere, but Dumbledore corrected him in that he has six Horcruxes (the seventh residing within him), and that Harry had already destroyed the diary and Dumbledore already destroyed Marvolo Gaunt's ring, which he found in the Gaunt shack with magical enchantments and a terrible curse placed upon it. Dumbledore told Harry that Voldemort would not have made Horcruxes out of random, useless objects, but trophies with powerful magical history worthy of the honour.

Dumbledore told Harry that he would be prepared to bet that Helga Hufflepuff's cup and Salazar Slytherin's locket were also made Horcruxes, and also possibly something of Rowena Ravenclaw's. The only relic of Godric Gryffindor, his sword, was with Dumbledore and thus was unable to be made a Horcrux. Dumbledore also mentioned that he believed Voldemort made his snake, Nagini, a Horcrux, and was one Horcrux short before entering Harry's parents' house with the intention of killing Harry, circumventing the prophecy, and making a Horcrux with Harry's death. Dumbledore also told Harry that Voldemort was so immersed in evil and that the pieces of his soul had been detached for so long that he did not feel when the Horcruxes were destroyed.

Despite this, it was said that his anger was terrible upon discovering the diary's destruction. Dumbledore explained that Voldemort meant for the diary to be smuggled into Hogwarts, but Lucius was supposed to wait for Voldemort's say-so, which he never received, as Voldemort vanished shortly after giving him the diary. Voldemort didn't tell Lucius what it truly was, and so Lucius went ahead and planted the diary on Ginny Weasley in the hopes of getting Arthur Weasley discredited, Dumbledore thrown out of Hogwarts, and getting rid of the highly incriminating object at one time. He also explained that, even if Voldemort's Horcruxes were all destroyed, it would take a wizard with uncommon skill and power to defeat the Dark Wizard.



Harry believed he didn't have any uncommon skill or power, but Dumbledore contradicted him: Harry had the ability to love, and this was the power that the prophecy mentioned "the Dark Lord knows not". Dumbledore explained that what the prophecy said was only significant because Voldemort made it so, and that by choosing to kill Harry to circumvent the prophecy, Voldemort singled out the person who would be most dangerous to him. Dumbledore told Harry that not all the prophecies in the Hall of Prophecy have been fulfilled; the prophecy about Harry and Voldemort would have meant nothing if Voldemort hadn't chosen to act on it. If Voldemort hadn't killed Harry's parents, he would not have given Harry the desire for revenge nor the sacrificial protection given to him by his mother when she died for him. Not only did Voldemort handpick the man most likely to finish him, but also gave him the tools for the job.



Dumbledore told Harry that, in fact, Harry was protected by the ability to love, and that despite all the temptation and suffering he had endured, he had never had the desire to join Voldemort. Indeed, Harry could flit into Voldemort's mind without harming himself, whereas it was mortal agony when Voldemort tried to possess Harry, as he discovered at the end of the Battle of the Department of Mysteries. In Voldemort's hurry to mutilate his own soul, he underestimated the power of a soul that is untarnished and whole. Dumbledore explained to Harry that Harry has got to kill Voldemort in the end, but not because of the prophecy; instead, Harry has got to kill Voldemort because he would never rest until he saw Voldemort finished at his own hands. The prophecy didn't mean Harry had to do anything; it gave him the choice because Voldemort marked him as his equal. However, Dumbledore informed Harry that Voldemort continued to set store by the prophecy, thus making it inevitable that either Harry and Voldemort would kill each other in the end. Harry realises that what Dumbledore was trying to tell him was the difference between being dragged in to face your destruction or to walk in with your head held high, and that, between these two options, there was a great deal of difference.

Behind the scenes

 * In the film version of Harry Potter and the Half-Blood Prince, only Dumbledore's first memory (at the orphanage) and both the fake and real versions of Horace Slughorn's memory are shown. All of the other memories are omitted.
 * In the film, only the diary, the ring, and the locket are discussed. No mention is made of the cup, the object of Ravenclaw's, or Nagini.
 * In the book, Dumbledore says how Voldemort would collect "trophies", and therefore would not use random items (like tin cans and old potion bottles) to make Horcruxes, however, in the film, Dumbledore says that Horcruxes "Could be anything. Most common place of objects.", and then lists a ring and a book as examples. Though in a deleted scene for Harry Potter and the Deathly Hallows: Part 1, Harry says that Dumbledore's theory was that Voldemort would not make random objects into Horcruxes.
 * Furthermore, in the Half-Blood Prince film, Dumbledore says that the Horcrux ring belonged to Voldemort's mother, not his grandfather, though later in Deathly Hallows: Part 1, Harry says that, according to Dumbledore, the ring belonged to his grandfather; also, he had knowledge that the locket belonged to Voldemort's mother, even though no Gaunt memory was shown in the film.

Appearances

 * Harry Potter and the Half-Blood Prince
 * Harry Potter and the Half-Blood Prince (film)
 * Harry Potter and the Half-Blood Prince (video game)
 * Harry Potter and the Deathly Hallows

Leçons de Dumbledore