Here you will find a Harry Potter and the Chamber of Secrets summary (J.K. Rowling's book).
We begin with a summary of the entire book, and then you can read each individual chapter's summary by visiting the links on the "Chapters" section.
P.S.: As an Amazon Associate, we earn money from purchases made through links in this page. But the summaries are totally free!
Last Updated: Monday 1 Jan, 2024
During a dreary summer spent with his sole remaining relatives, the Dursleys, Harry is warned by Dobby, a house-elf, against returning to his magical school, Hogwarts. Ignoring the warning, Harry causes chaos in the kitchen, inciting the Dursleys' rage and leading to his confinement for the summer. However, Harry's friend, Ron Weasley, rescues him with a flying car, and Harry spends the rest of the summer with the welcoming Weasley family. On their return to Hogwarts, Harry and Ron encounter obstacles and take the flying car all the way to the school, landing haphazardly and thus earning detention. Upon their return to Hogwarts, Harry and Ron become embroiled in a mystery when strange petrifications begin occurring. During a Quidditch match, Harry is hit by a bewitched ball, causing him to lose all the bones in his arm. In an unexpected twist, Harry discovers he can speak Parseltongue, a rare ability to communicate with snakes, traditionally linked with the Slytherin family. As more students are petrified, suspicion falls on Harry due to his newly unveiled ability. Aware of their need to find the true culprit, Harry, Ron, and Hermione utilise a potion known as Polyjuice to impersonate Slytherin students and question their suspect, Malfoy. Learning that he is not the heir of Slytherin, they find themselves at a dead end. However, Harry's discovery of a mysterious diary leads to a shocking revelation about the Chamber of Secrets, its monster, and its true perpetrator. Braving the Chamber, Harry defeats a basilisk with the help of a phoenix and a magical sword, saving Ron's sister Ginny and destroying the diary, which turns out to be a vessel for a younger version of the evil Voldemort. After emerging victorious, Harry manages to free Dobby from his master, Lucius Malfoy, bringing the tumultuous school year to a satisfying end.
A quarrel ensues at 4 Privet Drive, with Vernon Dursley angrily scolding his nephew Harry Potter over his pet owl Hedwig's loudness. His overweight and pampered son, Dudley Dursley, demands more bacon, leading Harry to sarcastically remind him to say 'please'. This prompts a turbulent reaction from the family. The narrator addresses the cause of the turmoil. Harry, a wizard, is spending his summer holidays with the Dursleys after his first year at Hogwarts School of Witchcraft and Wizardry. Harry's wizarding paraphernalia, including spellbooks, broomstick, wand and cauldron, were locked up in a cupboard by Uncle Vernon. The Dursleys, or "Muggles”, as non-magic folk are called, had to take Harry in after his parents were murdered by the wicked wizard, Lord Voldemort. Harry bears a lightning-bolt scar on his forehead, a remnant from surviving Voldemort's curse, which led to the downfall of Voldemort and made Harry a renowned figure in the wizarding world. On the day the story starts, Harry is celebrating his twelfth birthday, unnoticed by the Dursleys who are more engrossed in preparing for a crucial dinner party, which Vernon hopes will secure him a business deal. Harry is asked to stay in his room and act as if he doesn't exist. Post breakfast, a disheartened Harry steps outside, missing his Hogwarts friends, Ron Weasley and Hermione Granger. He spots a set of large eyes peeking at him from a hedge. Before he could examine it, Dudley interrupts, mocking him for having no friends to wish him on his birthday. Harry calmly ignores Dudley’s taunts, which prompts Dudley to ask him what he's looking at. In response, Harry threatens to set the bush on fire, sending Dudley scurrying for safety. Aunt Petunia promptly punishes Harry by assigning him chores, gives him bread for dinner and sends him to his room. Harry finds a stranger on his bed as he enters his room.
A small creature with green eyes and bat-like ears, donned in a ragged pillowcase, identifies itself as Dobby the house-elf, the same being Harry had spotted in the bush earlier. Its intense emotional response to Harry's kind treatment results in loud crying which disrupts the dinner party downstairs. Dobby, compelled to punish himself each time he speaks ill of his masters, admits his obligation to serve them. Dobby is in awe of Harry's fame and kindness, but warns him about an impending danger at Hogwarts. Frustratingly, Dobby communicates only with nods or head shakes, further alarming Harry when he self-harms again. Harry is chastised by Vernon Dursley as the noise reaches downstairs. Harry conceals Dobby when Vernon arrives and discovers that Dobby has been intercepting his letters to prevent his return to Hogwarts. In desperation, Dobby enchants a pudding to levitate and then drop, hoping to dissuade Harry from leaving. The resulting mess incenses the Dursleys. Their fury escalates after an owl delivers a letter warning Harry of the consequences of using magic outside of school, leading to the departure of their guests and the dissolution of the drill deal. Harry, now feared by the Dursleys, is locked away with barred windows and a door flap for food delivery. His depression deepens as he dreams of imprisonment and taunting. A dream of his cage's bars being shaken awakens him to the sight of Ron Weasley, his best friend from Hogwarts, outside his window.
Awakened by a dream, Harry spots Ron Weasley, his best friend, in a flying car, piloted by his twin brothers Fred and George. Concerned by Harry's lack of response to his letters, Ron decides to rescue him from the Dursleys. The boys together remove the bars from Harry's window. Fred and George, notorious for their mischief, unlock Harry's door and quietly retrieve his trunk. They successfully escape through the window, but not before waking Uncle Vernon due to Hedwig's screeching. A tug-a-war between Vernon and the Weasleys follows, with the Weasleys succeeding and driving off into the night. Inside the car, Harry shares his encounter with Dobby. The twins reveal that house-elves are normally owned by rich, old wizard families, leading Harry to suspect Draco Malfoy, his arch-nemesis at Hogwarts, to have sent Dobby to hinder his return to school. The twins confirm that Lucius Malfoy, Draco's father, was a devout follower of Voldemort, the malevolent wizard. Discussion turns to Mr. Weasley, their father, who rectifies the damage caused by cursed objects in the Misuse of Muggle Artifacts Department at the Ministry of Magic. The twins clarify their father's fascination with Muggles, which prompted him to buy and bewitch the car. Arriving at The Burrow, the Weasleys' chaotic home, at daybreak, they are greeted by an irate and worried Mrs. Weasley. After warmly welcoming Harry, she scolds her sons and assigns them the task of de-gnoming the garden, which Harry decides to join. Mrs. Weasley seeks advice from a book by Gilderoy Lockhart and her fondness for him is evident. The process of de-gnoming involves removing small, gnome-like creatures from the bushes and throwing them into a nearby field. Harry initially tries to gently discard a gnome, but after it bites him, he resorts to hurling them. By the time the task is completed, Mr. Weasley returns from work. His excitement hearing about the flying car overshadows his guilt for enchanting it, despite his wife's anger. Ron shows Harry to his room, passing his younger sister Ginny, who clearly has a crush on Harry. Ron's room is filled with Quidditch posters, and he seems embarrassed about the state of his house. However, Harry is fascinated by everything.
Harry relishes his time at the magical Weasley residence, The Burrow, where everything is enchanted. Mr. Weasley, fascinated by non-magic people, or Muggles, frequently quizzes Harry about Muggle life. One day, they receive their school supply lists. Ginny Weasley, the youngest, becomes particularly clumsy around Harry. Percy, the eldest Weasley still at home, is introduced as a nerdy, harmless character. All the Weasley boys, barring Percy, spend a day practicing the wizard sport, Quidditch. Ron mentions their financial struggles, making Harry uncomfortable as he has substantial wealth inherited from his parents. Days later, Harry and the Weasleys use magical Floo powder to teleport via fireplace to Diagon Alley for their school shopping. Mispronouncing "Diagon Alley" due to ash in his mouth, Harry ends up in a sinister shop in Knockturn Alley. He hides and overhears Lucius Malfoy instructing the shop owner to sell certain suspicious items and admonishing his son, Draco, for complaining about Harry and Hermione Granger. After the Malfoys leave, Harry slips out and bumps into Hagrid who guides him back to Diagon Alley where the Weasleys and Hermione are waiting. At Gringotts Bank, Mrs. Weasley empties their vault to pay for school supplies, while Harry discreetly stashes his abundant wealth. They continue shopping and end up at Flourish and Blotts bookstore. There, celebrity wizard Gilderoy Lockhart is signing his autobiography. Recognizing Harry, Lockhart insists on a photo-op and reveals he'd be teaching at Hogwarts that year. The Malfoys arrive at the bookstore, insult the Weasleys' financial status and the Grangers' non-wizard heritage, leading to a fight between Mr. Weasley and Mr. Malfoy. After the fight is broken up, the Weasleys and Harry bid Hermione and her parents farewell, before returning to The Burrow.
Harry relishes his summer stay at The Burrow. On the eve of their departure for Hogwarts, they indulge in a sumptuous meal, launch magical fireworks, sip hot cocoa, and retire for the night. The ensuing morning is hectic with six children packing for school. Mr. Weasley's Ford Anglia, charmed to accommodate everyone and their belongings, is their ride. After a few trips back for overlooked items, they reach King's Cross to board the Hogwarts Express from platform nine-and-three-quarters. All the Weasleys successfully pass through the barrier, but it denies Harry and Ron entry. They miss the train but decide to chase it using the flying Ford Anglia. The airborne journey to Hogwarts is serene initially, with the duo gliding over clouds and keeping the Hogwarts Express in sight. As night falls, they grow restless and hungry. Then, the Anglia runs out of gas, plunging towards the Hogwarts lake. Despite their efforts, they crash into the Whomping Willow, a unique tree in the Forbidden Forest that retaliates when hit. Its ferocious branches lash out at the boys and the car. They gather their belongings and dash towards the Hogwarts castle, observing the "Sorting" ceremony from the outside. They notice Professor Snape's absence, but he suddenly emerges and ushers them into his office. Harry and Ron's explanation is cut short by Snape, who shows them a newspaper article about Muggles noticing a flying car and chastises them for damaging the Whomping Willow. Snape fetches Albus Dumbledore and Minerva McGonagall, leading to further reproof, detentions, and a reprieve to stay at Hogwarts. Snape is dissatisfied with their light punishment. The professors return to the feast, leaving behind sandwiches and pumpkin juice for the boys. After eating, Harry and Ron head back to Gryffindor Tower, entering through a portrait of a fat lady after uttering the secret password ("wattlebird," Hermione tells them). Their arrival creates a buzz in the common room, but they dodge Percy's reprimands and head to their rooms. Their roommates, Seamus Finnigan, Dean Thomas, and Neville Longbottom, greet them as heroes.
The morning after their late arrival, Ron and Harry face a miffed Hermione at breakfast. Their friends, however, are still awed by their feat. As the daily post arrives, Ron's elderly owl, Errol, delivers a red, smoking envelope - a Howler. When opened, Mrs. Weasley's voice booms through the hall, scolding Ron for damaging the car and risking his and Harry's lives; the whole school hears. Following the embarrassing incident, Hermione warms up to the boys. The trio then attend Herbology where they find Gilderoy Lockhart, in extravagant turquoise attire, giving unsolicited advice to Professor Sprout about the Whomping Willow. Lockhart pulls Harry aside, blaming himself for the boys' car stunt. He assumes Harry is seeking fame by being reckless, which leaves Harry insulted. In the greenhouse, Professor Sprout teaches them to repot Mandrakes, dangerous plants with restorative properties. The students protect their ears from the deadly cry of the infant Mandrakes with earmuffs. A Hufflepuff boy, Justin Finch-Fletchley, introduces himself, explaining that Lockhart's books convinced his parents to opt for Hogwarts over Eton. After dealing with the Mandrakes, the Gryffindors attend Transfiguration class where Ron's broken wand fills the room with foul smoke. Enroute to the Defense Against the Dark Arts class, a starstruck first-year, Colin Creevey, pounces on Harry for an autographed photo. Draco Malfoy stumbles upon them, making fun of Harry's sudden celebrity status and disparaging Ron's poverty. Lockhart intervenes, suggesting they all pose for a photo with Colin. Later, Lockhart advises Harry against giving autographs so early in his career. The class starts with a quiz based on Lockhart's life and books, followed by an assignment with pixies, which Lockhart fails to control. He leaves the trio to calm down the chaotic pixies.
Life at Hogwarts goes on uneventfully for Harry. He keeps his distance from Gilderoy Lockhart and Colin Creevey and Ron struggles with his faulty wand. One Saturday morning, Oliver Wood, the leader of the Gryffindor Quidditch team, wakes Harry for an early practice. On his way to the locker room, Colin asks Harry to explain Quidditch rules. Harry describes the roles of different players, the game's equipment and its similarities to water polo. After a lengthy strategy meeting in the locker room, the team steps out for practice. They are greeted by Ron, Hermione and Colin, who's snapping pictures from the stands. Wood suspects Colin to be a Slytherin spy as the Slytherin team suddenly arrives, interrupting their practice. The Slytherins, who've been gifted new broomsticks by Draco Malfoy's father, refuse to leave. Draco mocks Fred and George's worn-out broomsticks, provoking Hermione’s defense. Draco retorts by calling Hermione a "Mudblood", a highly offensive term that makes Ron attempt a spell on Draco, only to have it backfire and make him vomit slugs. Harry and Hermione escort Ron to Hagrid's cabin where they find a glum Hagrid bidding goodbye to Lockhart. Hagrid cheers up at their arrival and offers a basin for Ron's slug-vomiting. Upon hearing about Draco's insult, Hagrid dismisses it and jokingly asks Harry for an autograph. He also shows the students his magically grown pumpkins, even though Harry is aware that Hagrid is forbidden to use magic. Harry and Ron are then called for their pending detentions for the flying car incident. Ron has to assist the grumpy caretaker Filch in polishing trophies, while Harry is to help Lockhart with his fan mail. Both boys are unhappy with their tasks. During his detention, Harry hears a high, eerie voice saying, "Come to me.let me rip you.let me tear you", causing him great alarm. Lockhart hears nothing, leaving Harry to worry about the disturbing voice for the rest of the evening.
As October's rainy season begins, Harry finds himself conversing with Nearly-Headless Nick, the Gryffindor ghost, who has been denied from the Headless Hunt due to his semi-attached head. Their chat is cut short when Mrs. Norris, the caretaker's cat, appears, forcing Harry to escape Filch's scrutiny for muddy footprints. When caught by Filch, a loud crash distracts him and Harry glimpses a "Kwikspell" course for underpowered wizards on Filch's desk. Upon Filch's return, he panics, questioning if Harry saw the course, then surprisingly lets him go. Outside, Nick admits to causing the distraction with Peeves's help. Harry, grateful, agrees to attend Nick's 500th Deathday party and spread rumors about Nick’s frightening aura to the other beheaded spirits. At the party, Harry, Ron, and Hermione are unnerved by the ghostly festivities and the sight of Moaning Myrtle, a bathroom-resident ghost. Peeves, the poltergeist, hurls insults at Myrtle, causing her to flee the party in tears. As the living trio prepares to leave, an ominous voice echoes through the halls proclaiming time to kill. They rush towards the sound, finding a chilling message on the wall: "The Chamber of Secrets has been opened. Enemies of the Heir, Beware." Nearby, they discover Mrs. Norris, the caretaker's cat, hanging stiffly. As the corridors fill with people, Draco Malfoy threatens, "You'll be next, Mudbloods!"
Upon discovering his petrified cat, Filch accuses Harry of the crime. Dumbledore, however, intervenes, gathering Harry, Ron, Hermione, and Filch in Lockhart's office to examine Mrs. Norris. Despite Lockhart's confident reassurances and Dumbledore's explanation that the petrification is beyond a second-year student's abilities, Filch remains convinced Harry is guilty. Snape's suspicion is also piqued as he questions the trio on their whereabouts on the night of the attack. Justin Finch-Fletchley avoids Harry, while Ginny Weasley appears scared. In History of Magic class, Hermione persuades Professor Binns to share the history of the Chamber of Secrets. The class learns about Salazar Slytherin's conflict with the other Hogwarts founders and his creation of the Chamber, a secret place harboring a monster that only his heir could control. Binns dismisses the story as mere folklore. Harry becomes anxious, recalling how the Sorting Hat had considered placing him in Slytherin. The school's suspicion that he is somehow linked to Salazar Slytherin increases his distress. In search of clues, Harry, Ron, and Hermione investigate Myrtle's bathroom and notice spiders fleeing through the window. They cross paths with Percy Weasley, who reprimands them for suspicious behavior. Later, Hermione proposes making a Polyjuice potion to disguise themselves as Slytherins to uncover if Malfoy is the Heir of Slytherin. Despite Ron and Harry's initial skepticism, Hermione is persistent in her plan of accessing the potion's recipe from the library's restricted section.
Following the pixie fiasco, Lockhart uses pretend-play in his Dark Arts lessons. Hermione impresses Lockhart with her interest in his books, asking to borrow a special book from the library's restricted section. Lockhart, flattered, permits it and the trio secure the book, which describes the complex process of creating a Polyjuice potion. Eventually, only Hermione remains keen on creating the potion but convinces Harry and Ron to assist. The day of the Gryffindor-Slytherin Quidditch game arrives. Oliver Wood inspires his team, emphasizing their superior skill despite the enemy's better brooms. Once the game commences, Harry is persistently targeted by a Bludger. Despite the Weasley twins' protection, the rogue Bludger distracts them from the game, causing Gryffindor to concede many goals. Harry proposes the twins return to the game, while he deals with the rogue Bludger and searches for the Snitch. Malfoy, Slytherin's seeker, mocks Harry's evasive maneuvers against the Bludger, which allows Harry to spot the Snitch near Malfoy's face. Despite being hit by the Bludger, Harry quickly recovers, snatches the Snitch, wins the game, but lands painfully. Harry's victory is short-lived as Lockhart, attempting to fix Harry's broken arm, accidentally removes all bones. Harry is sent to the hospital wing. Later, Dobby visits Harry, confessing to sealing the train platform and bewitching the Bludger. He hoped these obstacles would force Harry to leave Hogwarts and avoid the danger of the reopened Chamber of Secrets. Dobby refuses to reveal more, and vanishes as Dumbledore and Professor McGonagall arrive, carrying the petrified Colin Creevey. Dumbledore solemnly confirms Dobby's warning - the Chamber of Secrets is open once more.
Harry wakes up in the hospital with a healed arm and rushes to relay the news about Dobby and Colin to Ron and Hermione in Moaning Myrtle's bathroom. They are in the middle of brewing the Polyjuice Potion. The school is in chaos due to Colin's incident, leaving Ginny Weasley shaken and Neville Longbottom toting protection charms out of fear. Percy is extremely cheerful for some reason. During Potions class, Harry causes a distraction by tossing a firecracker into a Slytherin's cauldron, which splatters swelling potion on several students. This diversion allows Hermione to steal Polyjuice ingredients from Snape's personal stash. When the potion's effects wear off, an angry Snape threatens expulsion to the culprit. A week after, the trio attends a new student dueling club led by Lockhart. Snape disarms Lockhart during a demonstration, which he brushes off as a deliberate move. The students are then paired off, with Hermione against a big Slytherin girl, Millicent, and Harry against Malfoy. During their duel, Malfoy conjures an aggressive snake which is unintentionally aggravated by Lockhart's intervention. Harry impulsively commands the snake in Parseltongue, startling his classmates and making him question his link to Salazar Slytherin. The following day, Harry seeks Justin to clarify the snake incident but overhears Hufflepuffs, including Ernie Macmillan, discussing his potential dark powers and claiming he's the heir. The encounter agitates Harry. As he heads back, he bumps into Hagrid carrying a dead chicken and stumbles upon the petrified bodies of Justin and Nearly-Headless Nick. The alarming situation draws the attention of students and teachers, prompting Professor McGonagall to escort Harry to Dumbledore's office.
Despite his fear, Harry is awestruck by Dumbledore's office. He tries on the Sorting Hat and is reminded he could have excelled in Slytherin. He spots a bird which suddenly self-ignites. Dumbledore explains it's Fawkes, his phoenix, undergoing rebirth. The headmaster reveals the unique abilities of phoenixes, which include loyalty, strength, and healing tears. Hagrid storms in to defend Harry, but Dumbledore assures him he doesn't suspect Harry of petrifying the students. When asked if he has anything to share, Harry denies. With the school still in fear, Fred and George lighten the mood by jokingly referring to Harry as the "Heir of Slytherin." As the term concludes, the trio prepare for their Polyjuice Potion expedition on Christmas day. They leave sleeping potion-laced cakes for Malfoy's friends, Crabbe and Goyle, to consume. After hiding the unconscious pair, they take hairs for the potion. They transform into the boys, with Hermione staying back. Not knowing the location of the Slytherin common room, they wander until Malfoy shows them the way. In the common room, Malfoy discusses an article about Ron's father being penalized for enchanting a Muggle car. He also shares his wish to assist the Heir, and mentions a hidden chamber in his family's home. Just as the potion's effect starts fading, they leave and return to Hermione, who has turned into a cat due to a hair mixed in her potion. Despite Moaning Myrtle's enjoyment of Hermione's predicament, they convince her to head to the hospital wing.
Harry and Ron stumble upon a flooded Moaning Myrtle's bathroom while returning from visiting a recuperating Hermione. Inside, they find a diary belonging to T.M. Riddle floating in the toilet. Ron recognizes the name from a trophy he had cleaned during detention, awarded fifty years ago for special services. Harry senses a connection to the diary and decides to keep it. After Hermione recovers, they show her the diary and she deduces that Riddle must have caught the Heir of Slytherin who opened the Chamber of Secrets around the same time. As February begins, the school atmosphere settles. No new attacks have occurred and the Mandrakes, crucial for healing the petrified, are maturing. On Valentine's Day, Lockhart decorates the hall in pink and hires dwarves to deliver messages of love. Harry receives a singing valentine, seemingly from a blushing Ginny Weasley, but in the commotion, his bag is emptied onto the floor. Only Riddle's diary remains unaffected by the spilled ink, leading Harry to discover that he can interact with the diary by writing in it. He starts a conversation with Tom Riddle who shares that he had been awarded for capturing the one who opened the Chamber of Secrets. Riddle invites Harry to see his memory of the event. Harry agrees and is transported to the headmaster's office in Riddle's memory, where Riddle's request to stay at school over summer is denied due to the danger posed by the Chamber. Harry then observes Riddle encounter a youthful Dumbledore before witnessing a confrontation between Riddle and a young Hagrid. Hagrid is trying to hide something in a box and insists it's innocent, but Riddle accuses him of harboring the monster from the Chamber. Riddle opens the box to reveal a large spider, at which point Harry's visit to the past ends. He rushes to share this revelation with Ron.
Harry, Ron, and Hermione are deep in the mystery of the diary and the potential involvement of Hagrid. Despite their suspicions, they choose not to approach Hagrid unless another attack happens. Life at Hogwarts carries on, with the second-year students choosing their next year's subjects and the unpredictable behavior of the maturing Mandrakes. The looming Hufflepuff-Gryffindor Quidditch match adds a sense of normalcy. However, the night before the match, Harry discovers his room has been ransacked and Riddle's diary is missing, leading them to believe a Gryffindor is responsible. On the match day, Harry hears the strange voice again. Hermione, having a sudden realization, rushes off to the library. As Harry prepares for the match, Professor McGonagall halts the game. She directs everyone back to their houses and leads Harry and Ron to the hospital wing, where they find Hermione and a Ravenclaw prefect, Penelope Clearwater, petrified. The school imposes new rules of staying in the common rooms after six P.M. and being accompanied by teachers everywhere. With the threat of Hogwarts closing, Harry and Ron decide it's time to visit Hagrid under the cover of the invisibility cloak. Under the cloak, the boys reach Hagrid's cabin late that night and hide as Dumbledore and Cornelius Fudge, the Minister of Magic, enter. Fudge insists on sending Hagrid to Azkaban, a terrible wizard prison, until the current events are resolved. Despite Dumbledore's trust in Hagrid, Fudge worries that his unclear past with the Chamber of Secrets makes him a primary suspect. When Lucius Malfoy arrives, he informs Dumbledore that the school governors want him to resign as headmaster. Dumbledore agrees without protest, leaving with the cryptic words, "You will find that I will only truly have left this school when none here are loyal to me. You will also find that help will always be given at Hogwarts to those who ask for it." Hagrid hesitantly departs, leaving behind two clues for Harry and Ron: to follow the spiders and to feed his dog, Fang.
As spring blooms at Hogwarts, Harry can't shake off his fear about the castle's mysteries. He is unsure about how to act on Hagrid's hint about the spiders and Dumbledore's words on help and loyalty. Malfoy, on the other hand, is pleased with Dumbledore's departure and proposes Snape for headmaster. In a Herbology class, Ernie Macmillan withdraws his suspicion of Harry after Hermione's attack, expressing regret for his accusations. During the same class, Harry spots spiders heading towards the Forbidden Forest, which he points out to a reluctant Ron. Later, in Lockhart's defense against the dark arts class, Lockhart brags about the school's safety post Hagrid's removal, further upsetting Ron and Harry. Both decide to follow the spiders into the forest that night after seeing Hermione's vacant seat and recalling Lockhart's allegations against Hagrid. Covered by the invisibility cloak, Harry, Ron, and Fang step into the forest. They trail some lone spiders into the depths of the forest. Hearing a large movement, they are relieved to find it's Ron's old, wild-running Ford Anglia that had collided with the Whomping Willow. Just as they're about to continue their trail, they're seized by three giant spiders. Both boys are terrified, especially Ron who has a deep fear of spiders. The spiders transport them to a clearing housing a huge domed web and an aged, blind spider, Aragog. Initially, Aragog dismisses the boys to be killed, but on learning they were sent by Hagrid, he engages in a conversation. Aragog reveals that he was falsely accused as the Chamber's monster whereas he was merely a pet of Hagrid. The actual monster is one that spiders dread and don't dare to name. Aragog also discloses the monster's ancient victim was found in a restroom, post which he was freed into the forest by Hagrid. Despite sharing this information, Aragog encourages his offspring to devour the boys and Fang. Just when they thought they were doomed, the Weasley's car comes to their rescue, allowing them to escape the forest. Back in the dormitory, the boys are disheartened by the lack of new leads. However, lying in his bed, Harry speculates that the girl discovered in the toilet half a century ago could be Moaning Myrtle.
Harry and Ron attempt to figure out a plan to question Moaning Myrtle about her sudden death. All students are in shock when Professor McGonagall announces the upcoming exams. Amidst the chaos, the preparation of the Mandrakes to cure the petrified students is announced, causing joy amongst students. Ginny Weasley, looking worried, tries to divulge something to Harry and Ron but is silenced by her brother Percy, who insists the information is unrelated to the Chamber. Later, they manage to convince Lockhart to let them walk to class alone. They plan to go to Myrtle's bathroom but are stopped by McGonagall. They lie about visiting Hermione in the infirmary, where they find a note about the basilisk in her hand. The note reveals that the basilisk is the creature in the pipes and is responsible for the strange occurrences. As they head to show McGonagall the note, they overhear that Ginny has been taken into the Chamber of Secrets. The school gets ready to shut down, and the teachers challenge the boastful Lockhart to deal with the monster. When Harry and Ron find Lockhart packing his bags, he admits that he's a fraud and attempts to erase their memories. However, Harry disarms him and, with Ron, forces him into Myrtle's bathroom. They learn that Myrtle's death was caused by a large, yellow-eyed creature. Harry, Ron, and a reluctant Lockhart descend into the pipe revealed by a snake-engraved tap. They find a large snakeskin inside the pipe. Lockhart, grabbing Ron's wand, tries to wipe out their memories but ends up erasing his own and causing a rockfall that separates Harry from the others. Despite the isolation, Harry continues alone and eventually comes across a wall with snake engravings, which he commands to open before stepping inside.
In the serpent adorned Chamber of Secrets, Harry finds an unconscious Ginny near a colossal statue of Salazar Slytherin. Observing them is Tom Riddle's ghostly persona, who appears indifferent to Ginny's critical condition. Harry feels uneasy when Tom seizes his wand but is more focused on escaping the Chamber with Ginny, safe from the lurking basilisk. Tom reveals that his diary helped him gain power over Ginny. He puppeteered her actions, causing her to slay Hagrid's roosters and unseal the Chamber. As Tom grew stronger, he hoped to use another person to fulfill Slytherin's unfinished agenda. When Harry took possession of the diary, Tom was thrilled, and by the time Ginny reclaimed it, she was entirely under its influence. Now Tom is free from the diary's pages. Tom discloses his true identity by rearranging the letters in his name to read "I am Lord Voldemort," claiming he is the superior wizard. Harry counters, asserting Dumbledore's superiority, which infuriates Tom. Suddenly, Dumbledore's phoenix, Fawkes, arrives with the Sorting Hat. Tom scoffs at these items and challenges Harry to explain his survival of Voldemort's attack. Harry retorts that his mother's sacrificial love saved him, to Tom's amusement, who then notes their striking similarities before summoning the basilisk for a duel. With the basilisk's approach, Fawkes blinds the beast. Amid the chaos, the Sorting Hat lands in Harry's hands and produces a sword. Harry slays the basilisk with the sword, but not before getting injured by a fang. Fawkes cries healing tears on Harry's wound, thwarting Tom's satisfaction. Tom attempts to kill Harry, but Fawkes drops the diary in Harry's hands, and he destroys it using the basilisk tooth, causing Tom to vanish. Ginny regains consciousness, and with Fawkes' guidance, they exit the Chamber. They meet Ron and an amnesiac Lockhart. Fawkes takes them to safety by flying them out of the Chamber. Myrtle, who had a crush on Harry, expresses her disappointment over his survival. Finally, Fawkes leads them to Professor McGonagall's office.
Harry, Ron, Ginny, and Lockhart reach McGonagall's office, where they encounter Dumbledore and the Weasleys. The Weasleys rush to embrace Ginny and Harry recounts the events in the Chamber of Secrets, leaving out the part about Ginny and the diary. When pressed about how Voldemort manipulated Ginny, Harry is encouraged by Dumbledore to reveal the role of the diary. Dumbledore then sends Ginny off to the infirmary, informs everyone about the recuperating petrified victims, and announces a celebratory feast. He awards Harry and Ron 200 points each for their bravery before sending Lockhart to the infirmary under Ron's supervision, and requests to speak with Harry alone. In private, Dumbledore explains to Harry that his loyalty brought the phoenix, Fawkes, to his aid in the Chamber. Addressing Harry's concerns about his similarities with Tom Riddle, Dumbledore reassures him that he ended up in Gryffindor because of his choices, not his abilities. He adds that only a true Gryffindor could have retrieved Godric Gryffindor's sword from the Sorting Hat. Lucius Malfoy soon barges in, with his house-elf, Dobby, in tow. Lucius is angry about Dumbledore's return, but the Headmaster calmly tells him that he was reinstated by the repentant school governors. Harry soon realizes from Dobby's reactions that Lucius snuck the diary into Ginny's books. Upon being accused, Lucius storms out, leaving behind a sock Harry had wrapped the diary in. Picking up the discarded sock, Dobby is inadvertently freed from servitude, and he gratefully thanks Harry before disappearing. The celebratory feast is a joyous occasion. Hagrid is back, exams are scrapped, and Lockhart is dismissed from the staff. Gryffindor wins the House Cup, and Lucius is ousted as governor. The remainder of the term passes peacefully. On the train ride home, Harry learns from Ginny that she saw Percy kissing his girlfriend, Penelope Clearwater, much to Fred and George's delight. Finally, they all return to the Muggle world for the summer break.