Harry Potter and the Methods of Rationality

Plot

Harry James Potter-Evans-Verres is the adopted son of scientist Michael Verres and his wife Petunia, Harry's biological aunt. On his eleventh birthday, Harry receives a letter inviting him to attend Hogwarts School of Witchcraft and Wizardry. Michael is sceptical, but Petunia confesses that Harry's parents were wizards. Hogwarts professor Minerva McGonagall comes to the Verres home and demonstrates the existence of magic by transforming into a cat; witnessing this violation of conservation of energy, Harry realises his scientific understanding of the universe was incomplete. McGonagall tells Harry that his parents were killed by Lord Voldemort, leader of wizard supremacist faction the Death Eaters. Voldemort's killing spell backfired when he attacked Harry, leaving him the "Boy-Who-Lived", a celebrity in the wizarding community. Harry infers from McGonagall's careful answers that Voldemort is alive and linked to Harry by a prophecy.

On the train to Hogwarts, Harry meets the pure-blood wizard Draco Malfoy; alarmed by Draco's backward attitudes towards wizards born to "Muggle" (non-magical) parents, he resolves to one day reform the Ministry of Magic. On meeting the Muggle-born witch Hermione Granger, Harry is impressed by her intelligence, and the two decide to collaborate on magical research. At Hogwarts, the magical Sorting Hat sorts Hermione into Ravenclaw (the House associated with intelligence) and Draco into Slytherin (associated with cunning). Harry's inquiries confound the hat, which sorts him into Slytherin before declaring this a joke and correcting it to Ravenclaw. When removing the hat, Harry hears a hiss inviting him to find a "secret" by "speaking to a snake". He deduces that this is a secret message left by Hogwarts co-founder Salazar Slytherin, only to be repeated under certain conditions. Later, Headmaster Albus Dumbledore calls Harry to his office and gives him a rock belonging to Harry's father, insisting that Harry carry it at all times; Harry asks McGonagall to teach him how to transfigure it into a diamond so that he can wear it as a ring.

The next morning, Harry finds a series of notes giving him points for actions, seemingly part of an unknown game. Attempting to determine their origin, he encounters a group of Slytherins bullying another student; bluffing that he possesses great powers, Harry snaps his fingers, and is taken aback when a pie appears, hitting one Slytherin in the face. Still following the notes, Harry visits McGonagall, whom he tells about the hat's message. She says that she believes the message was last heard fifty years ago, and led to the death of a student; impressed by Harry's mature response, she offers him a Time-Turner, a portable time machine he can use to treat his 26-hour sleep cycle. Returning to his dorm, he finds that an anonymous donor has left him his father's invisibility cloak; realising that he was the game controller, he travels back in time to leave himself the notes and invisibly ambush the Slytherin boy with the pie, knowing he can use the Time-Turner and cloak to continue the charade of omnipotence.

After being verbally abused by Professor Severus Snape, Harry reports him to Dumbledore. Deducing that Snape must also know Voldemort is alive, Harry uses this knowledge to bargain for a public apology from Snape. In Battle Magic class, Professor Quirinus Quirrell lambasts Harry for escalating the situation; to teach him the life skill of "knowing when to lose", he has Harry beg for mercy while other students beat and taunt him. Afterwards, Harry asks Quirrell if he is on the path to becoming a Dark Lord, and describes his plan to instead become a "Light Lord" through mastery of science. Discovering their shared love of space exploration, Quirrell shows Harry a vision of the cosmos. Draco is dismayed when Harry scientifically disproves Draco's family's belief that magical power is linked to wizard blood purity. Later, Harry makes another breakthrough, discovering that he can circumvent the magical restraint that only whole objects can be transfigured by conceiving of them as collections of particles in timeless physics.

In the new year, Quirrell arranges to have a Dementor – a dark creature capable of consuming souls – brought to Hogwarts so that students can practice casting the Patronus, a protective spell which manifests happy thoughts as an animal of light. Confronting the creature, Harry experiences a vivid flashback of his parents' murder. Realising that Dementors are the embodiment of Death, he uses the thought of humanity achieving immortality and spreading across the stars to conjure a Patronus in the form of a human, destroying the Dementor. After swearing Harry to secrecy, Quirrell – who cannot cast the Patronus – requests his help in rescuing Bellatrix Black, a woman tortured by Voldemort and condemned to life in the Dementor-guarded wizard prison Azkaban. They succeed, and Quirrell delivers Black to a safe house before he and Harry return to Hogwarts. Horrified by Azkaban, Harry resolves to eventually have it destroyed. Learning of the break-out, Dumbledore concludes that Voldemort is responsible and attempting to return to power.

Draco claims that Hermione attempted to kill him. When she confesses to the crime, Harry realises that someone has altered her memory, framing her. Dumbledore speculates that she was possessed by Voldemort, and that he is currently in Hogwarts, where Dumbledore is hiding an artefact that represents Voldemort's best chance at resurrection. At Hermione's trial, Harry agrees to pay his inheritance of gold to House Malfoy to cancel Hermione's blood debt to them.

During the Easter holidays, Hermione suggests that she and Harry investigate the Philosopher's Stone, an artefact capable of creating gold and the elixir of life; however, they have an argument when Harry lets slip that he had been conducting experiments with Draco. Later, the caretaker announces that he has found a troll in the dungeon. Connecting this to the attempt to frame Hermione, Harry realises that she is in danger. Instructing his Patronus to locate her, he follows it to a terrace where he finds that Hermione has been attacked, her legs partly eaten by the troll, a huge humanoid monster with regenerative abilities. Harry levitates the jewel from his ring up one of the troll's nostrils and transfigures it back into his father's rock, killing it. He attempts to help Hermione, but is unable to find any medical or magical method to save her; she dies moments later. The next morning, Hermione's body goes missing.

Caught drinking unicorn blood, Quirrell reveals to Harry that he is dying. Harry suggests that he adapt the Horcrux spell, dark magic allowing a wizard to tie a fragment of their soul to an object with a human sacrifice, but Quirrell dismisses the idea, saying it merely duplicates memory at the moment of creation with no continuity of consciousness. Later, Harry receives a message seemingly from himself. Following its instructions, he finds a secret passage where he meets Quirrell, who says he urgently needs Harry to help him retrieve the Philosopher's Stone from the magic mirror where it is hidden. Finally collating a number of suspicious coincidences surrounding Quirrell, Harry realises that the professor is Voldemort. Before Harry can escape, Voldemort forces him into the passage at gunpoint, explaining that his real name is Tom Riddle; Voldemort was simply a persona he created for fun, and Quirrell one he assumed for convenience. Riddle says that he enhanced the Horcrux spell years ago, allowing him to truly anchor his consciousness without cost, and performed it hundreds of times. After hearing the prophecy that the newborn Harry would destroy or be destroyed by him, Riddle performed the Horcrux spell on the infant, overwriting Harry's brain with his own cognitive patterns to create an equal with whom to share rulership of magical Britain; however, he misjudged the spell, losing his body as a result. Riddle says that the Stone's true power is making transfiguration permanent, allowing unlimited human transfiguration. Harry agrees to help him retrieve it on the condition that he resurrect Hermione.

At the mirror, Quirrell triggers a trap set by Dumbledore to protect the Stone, but the headmaster reverses it and sacrifices himself to save Harry's life. Taking Harry to Voldemort's grave, Riddle uses the Stone to reanimate and return to his original body. Voldemort resurrects Hermione, whose body Harry had transfigured into a ring in the hope of eventually saving her. After imbuing Hermione with a troll's regenerative ability, Voldemort kills the real Quirrell as a sacrifice to grant her a Horcrux. When Harry attempts to ambush Voldemort and escape, Voldemort summons his Death Eaters as backup, threatening to kill Harry unless he conveys the secret powers the prophecy said he would have. Seeing no peaceful option, Harry partially transfigures the tip of his wand into a filigree of carbon nanotubes, which he rapidly tightens to simultaneously decapitate the Death Eaters and cut off Voldemort's hands. Harry erases the unconscious Voldemort's memories, then transfigures him into a ring. Back at Hogwarts, Harry fakes a vision in which Voldemort sacrifices his servants in a dark ritual, with Quirrell dying in a heroic effort to stop him, redirecting the resurrection spell to Hermione. Harry devises a plan to grant all wizards and Muggles eternal youth and perfect health using the Stone, eradicating needless death. After telling the now-invincible Hermione the truth, he resolves to ask for her help in destroying Azkaban and the Dementors.

Reception

HPMOR has been reviewed positively by science fiction author David Brin and fantasy author Rachel Aaron. According to The Atlantic, HPMOR "caused uproar in the fan fiction community, drawing both condemnations and praise".

According to a review in the Hindustan Times, HPMOR is a "thinking person’s story about magic and heroism", and the conflict between good and evil is portrayed as a battle between knowledge and ignorance. The book lasts a single year, covering the same amount of time as one volume of Rowling's seven-part series.