The book

Harry Potter and the Chamber of Secrets is the second instalment in the Harry Potter series written by J. K. Rowling. The plot follows Harry's second year at Hogwarts School of Witchcraft and Wizardry, during which a series of messages on the walls on the school's corridors warn that the "Chamber of Secrets" has been opened and that the "heir of Slytherin" will kill all pupils who do not come from all-magical families. These threats are followed by attacks which leave residents of the school "petrified" (that is, frozen). Throughout the year, Harry and his friends Ron Weasley and Hermione Granger investigate the attacks, and Harry is confronted by Lord Voldemort, who is attempting to regain full power.

The book was published in the United Kingdom on 2 July 1998 by Bloomsbury and in the United States on 2 June 1999 by Scholastic Inc. Although Rowling found it difficult to finish the book, it won high praise and awards from critics, young readers and the book industry, although some critics thought the story was perhaps too frightening for younger children. Some religious authorities have condemned its use of magical themes, while others have praised its emphasis on self-sacrifice and on the way in which a person's character is the result of the person's choices.

Several commentators have noted that personal identity is a strong theme in the book, and that it addresses issues of racism through the treatment of non-magical, non-human and non-living characters. Some commentators regard the diary as a warning against uncritical acceptance of information from sources whose motives and reliability cannot be checked. Institutional authority is portrayed as self-serving and incompetent.

The film version of Harry Potter and the Chamber of Secrets, released in 2002, became the third film to exceed $600 million in international box office sales and received generally favourable reviews. However, The Lord of the Rings: The Two Towers won the Saturn Award for the Best Fantasy Film. Video games loosely based on Harry Potter and the Chamber of Secrets were also released for several platforms, and most obtained favourable reviews.

In the first novel in the Harry Potter series, the main character, Harry Potter, has struggled with the difficulties that come with growing up and the added challenge of being a famous wizard. When Harry was a baby, Voldemort, the most powerful evil wizard in living memory, killed Harry's parents but mysteriously vanished after trying to kill Harry. This results in Harry's immediate fame, and his being placed in the care of his muggle, or non-magical, relatives Aunt Petunia and Uncle Vernon.

Harry enters the wizarding world at the age of 11, enrolling in the Hogwarts School of Witchcraft and Wizardry. He makes friends with Ron Weasley and Hermione Granger, and is confronted by Lord Voldemort trying to regain power.

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.