In 1992, while the Dursley family—his uncle Vernon, aunt Petunia, and cousin Dudley—entertain a potential client for Vernon’s drill-manufacturing company Grunnings, Harry Potter reminisces upon the events of the previous year, including his enrolment in Hogwarts School of Witchcraft and Wizardry and confrontation with Lord Voldemort (the Dark wizard whose reign seemingly ended when he killed Harry’s parents and attempted but failed to kill Harry himself), and laments the fact that the best friends he made at the institution have not written to him, even for his birthday, on which the novel opens.
Just as Harry is starting to anticipate his return to Hogwarts School, an impish but loyal house-elf named Dobby arrives out of nowhere to warn Harry against the decision to return to the wizarding world, citing grave danger as the reason, revealing that he had been intercepting Harry's letters from his friends, and inciting Harry’s gravest punishment yet when he smashes a dessert crafted by Petunia for the dinner party and frames it on Harry himself. Ron Weasley arrives with his twin brothers Fred and George to perform a jailbreak in their father Arthur’s enchanted Ford Anglia and to deposit him at their family home the Burrow for the remainder of his holidays. Harry and the rest of the Weasleys—mother Molly, third eldest son Percy, and daughter Ginny (who has a crush on Harry)—travel to Diagon Alley, where they are reunited with Hermione Granger and introduced to Lucius Malfoy, father of Harry’s school nemesis Draco, and Gilderoy Lockhart, a conceited autobiographer who has been appointed Defense Against the Dark Arts professor. As Harry and Ron plan to depart with the rest for Hogwarts School, the barrier within King’s Cross station that separates Muggles from wizards refuses to allow them passage, forcing them to fly Arthur’s car to the school, where they crash into a sentient willow tree on the grounds.
The crash lands them in hot water with headmaster Albus Dumbledore and Minerva McGonagall, Head of Gryffindor House and the Transfiguration professor, who doesn’t expel them in spite of the clear breach of magical law but does assign them to detentions: Ron must clean the school trophies in the trophy room, and Harry must help the lunatic Professor Lockhart with addressing his fan mail. Lockhart’s classes turn out to be as obsessed with the man as he is with himself, as proven by a “hands-on” training experience with a pack of destructive pixies (small, bluish creatures that exist to cause mayhem), and Harry learns that prejudice exists in the wizarding world by the way of blood status: Those with “pure” blood (only wizarding heritage) have the advantage over and condescend to those with Muggle parentage. Harry also begins hearing an unnerving voice (one only he can hear) seemingly coming from the walls of the school itself, and during a “death-day party” for the Gryffindor ghost, the trio happens upon a petrified Mrs. Norris, the cat belonging to school caretaker Argus Filch, and a warning scrawled across one of the walls: “The chamber of secrets has been opened. Enemies of the heir, beware.”
Rumours fly around the school regarding the history of the Chamber of Secrets, and for Harry and his friends, the answer comes by way of Cuthbert Binns, the ghostly professor of History of Magic: The Chamber of Secrets, which houses a terrible monster, was created by one of the school’s founders, Salazar Slytherin, after a fundamental disagreement with the others (Godric Gryffindor, Helga Hufflepuff, and Rowena Ravenclaw), believing that students of non-magical parentage should be refused entry to the school. When a Bludger, one of the balls involved in Quidditch, chases after Harry instead of zigzagging toward any player it can hit, breaking his arm, Dobby returns in the middle of the night to visit Harry in the hospital wing, revealing that it was he who charmed the Bludger and sealed the gateway at King’s Cross and that the Chamber of Secrets had been opened before. Another attack occurs, this time to a first-year Gryffindor named Colin Creevey who idolises Harry, and the school enters panic mode, setting up a dueling class for the students (led by Lockhart and Potions master/Head of Slytherin House Severus Snape), during which it is revealed that Harry is a 'Parselmouth', meaning he has the rare gift to speak to snakes.
This sparks the rumour mill yet again, as students around the school suspect Harry of being the Heir of Slytherin (as Slytherin was also a parselmouth), and circumstantial evidence to support this theory arrives in the form of another attack, this time on Hufflepuff second-year Justin Finch Fletchley and the Gryffindor ghost. Harry, Ron, and Hermione begin to suspect that Draco is behind the attacks, given his family history of remaining well within Slytherin ranks and open hostility toward Muggle-born students, and so Hermione concocts Polyjuice potion, which allows them to become Draco’s boorish lackeys, Vincent Crabbe and Gregory Goyle, for an hour to interrogate him. This comes to nothing, as Draco’s father only told his son the general facts of the previous opening of the Chamber and that it occurred fifty years previously. Meanwhile, Myrtle Warren, an existentially mopey ghost that haunts a bathroom, unwittingly provides a new clue in the form of a diary deposited in her stall—a diary, moreover, that belonged to Tom Riddle, a student who knows all too well about the Chamber, having been witness to a fellow student’s death fifty years ago. The culprit, he reveals to Harry, was none other than Rubeus Hagrid, now gamekeeper for Hogwarts School; when Hermione is attacked next, alongside a Ravenclaw prefect, the school is put on lockdown, and Dumbledore and Hagrid are forced to leave the premises.
Fortunately for Harry and Ron, Hagrid left a set of instructions: to follow the spiders currently fleeing into the Forbidden Forest, which they do, only to find the monster blamed for the attacks fifty years before, a massive spider named Aragog, who explains to the duo that the real monster is one that spiders fear above all others. Hermione provides the last set of clues that inform them of the monster’s identity: It is a basilisk, which is a giant serpent (hence Harry’s ability to understand it) that kills with a stare (although no one is dead because of various devices through which they indirectly saw the monster) and which spiders (such as Aragog and his offspring) fear above all others. Harry figures out from hints Aragog dropped that a student who died during the previous attacks is Myrtle, and when Ginny is apparently taken by the monster into the Chamber, they discover that the entrance is in the bathroom they’ve been using to make Polyjuice Potion. Harry, Ron, and Lockhart enter the Chamber, but the dunderheaded professor (who reveals that he’s a fraud) causes a rockfall upon attempt to modify the boys’ memories with Ron’s damaged wand, and Harry must enter alone. He arrives to find Ginny in a weakened state being watched over by a shadowy, ghostly Riddle, who explains that he is not only the heir of Slytherin, but also grew up to become Voldemort himself, before setting the basilisk upon Harry; Harry defeats the monster and destroys the diary, which makes Riddle disappear.
Harry, Ron, Ginny, and Lockhart return to the main castle and reunite with McGonagall, Dumbledore, and Mr. and Mrs. Weasley. Ginny, whose entrancement by Voldemort caused all of the petrification and troubles over the course of the year, is given a reprieve by Dumbledore, who reasons that greater wizards have been duped by Voldemort before and takes great interest in the qualities of the diary, which Harry gives to him. Lucius Malfoy bursts in after this meeting, demanding to know why and how Dumbledore has returned to the school and accompanied by Dobby, revealing the family to whom he is enslaved. The house-elf also provides Harry with unspoken cues regarding the diary’s ownership: While it was Tom Riddle’s, it had been in the Malfoys’ possession, and Harry returns it, devising a scenario involving his own sock that frees Dobby from the Malfoys’ employment. The petrified students are cured, the end-of-year exams are cancelled (much to Hermione’s chagrin), Hagrid comes back in the middle of the final feast, and Harry returns to Privet Drive in higher spirits than he last left it.
Rowling found it difficult to finish Harry Potter and the Chamber of Secrets because she was afraid it would not live up to the expectations raised by Harry Potter and the Philosopher's Stone (Harry Potter and the Sorcerer's Stone in the US). After delivering the manuscript to Bloomsbury on schedule, she took it back for six weeks of revision.
In early drafts of the book, the ghost Nearly Headless Nick sang a self-composed song explaining his condition and the circumstances of his death. This was cut as the book's editor did not care for the poem, which has been subsequently published as an extra on J. K. Rowling's official website. The family background of Dean Thomas was removed because Rowling and her publishers considered it an "unnecessary digression", and she considered Neville Longbottom's own journey of discovery "more important to the central plot".
Harry Potter and the Chamber of Secrets was published in the UK on 2 July 1998 and in the US on 2 June 1999. It immediately took first place in UK best-seller lists, displacing popular authors such as John Grisham, Tom Clancy, and Terry Pratchett, and making Rowling the first author to win the British Book Awards Children's Book of the Year for two years in succession. In June 1999, it went straight to the top of three US best-seller lists, including The New York Times'.
First edition printings had several errors, which were fixed in subsequent reprints. Initially Dumbledore said that Voldemort was the last remaining ancestor of Salazar Slytherin, instead of his descendant. Gilderoy Lockhart's book on werewolves is entitled Weekends with Werewolves at one point and Wanderings with Werewolves later in the book.
Harry Potter and the Chamber of Secrets was met with near universal acclaim. In The Times, Deborah Loudon described it as a children's book that would be "re-read into adulthood" and highlighted its "strong plots, engaging characters, excellent jokes and a moral message which flows naturally from the story". Fantasy author Charles de Lint agreed, and considered the second Harry Potter book as good as Harry Potter and the Philosopher's Stone, a rare achievement among series of books. Thomas Wagner regarded the plot as very similar to that of the first book, based on searching for a secret hidden under the school. However, he enjoyed the parody of celebrities and their fans that centres round Gilderoy Lockhart, and approved of the book's handling of racism. Tammy Nezol found the book more disturbing than its predecessor, particularly in the rash behaviour of Harry and his friends after Harry withholds information from Dumbledore, and in the human-like behaviour of the mandragoras used to make a potion that cures petrification. Nevertheless, she considered the second story as enjoyable as the first.
Mary Stuart thought the final conflict with Tom Riddle in the Chamber was almost as scary as in some of Stephen King's works, and perhaps too strong for young or timid children. She commented that "there are enough surprises and imaginative details thrown in as would normally fill five lesser books." Like other reviewers, she thought the book would give pleasure to both children and adult readers. According to Philip Nel, the early reviews gave unalloyed praise while the later ones included some criticisms, although they still agreed that the book was outstanding.
Writing after all seven books had been published, Graeme Davis regarded Harry Potter and the Chamber of Secrets as the weakest of the series, and agreed that the plot structure is much the same as in Harry Potter and the Philosopher's Stone. He described Fawkes's appearance to arm Harry and then to heal him as a deus ex machina: he said that the book does not explain how Fawkes knew where to find Harry; and Fawkes's timing had to be very precise, as arriving earlier would probably have prevented the battle with the basilisk, while arriving later would have been fatal to Harry and Ginny.
Rowling's Harry Potter and the Chamber of Secrets was the recipient of several awards. The American Library Association listed the novel among its 2000 Notable Children's Books, as well as its Best Books for Young Adults. In 1999, Booklist named Harry Potter and the Chamber of Secrets as one of its Editors' Choices, and as one of its Top Ten Fantasy Novels for Youth. The Cooperative Children's Book Center made the novel a CCBC Choice of 2000 in the "Fiction for Children" category. The novel also won Children's Book of the Year British Book Award, and was shortlisted for the 1998 Guardian Children's Award and the 1998 Carnegie Award.
Harry Potter and the Chamber of Secrets won the Nestlé Smarties Book Prize 1998 Gold Medal in the 9–11 years division. Rowling also won two other Nestlé Smarties Book Prizes for Harry Potter and the Philosopher's Stone and Harry Potter and the Prisoner of Azkaban. The Scottish Arts Council awarded their first ever Children’s Book Award to the novel in 1999, and it was also awarded Whitaker's Platinum Book Award in 2001. In 2003, the novel was listed at number 23 on the BBC's survey The Big Read.
Harry Potter and the Chamber of Secrets continues the examination of what makes a person who he or she is, which began in the first book. As well as maintaining that Harry's identity is shaped by his decisions rather than any aspect of his birth, Harry Potter and the Chamber of Secrets provides contrasting characters who try to conceal their true personalities: as Tammy Nezol puts it, Gilderoy Lockhart "lacks any real identity" because he is nothing more than a charming liar. Riddle also complicates Harry's struggle to understand himself by pointing out the similarities between the two: "both half-bloods, orphans raised by Muggles, probably the only two Parselmouths to come to Hogwarts since the great Slytherin."
Opposition to class, death and its impacts, experiencing adolescence, sacrifice, love, friendship, loyalty, prejudice, and racism are constant themes of the series. In Harry Potter and the Chamber of Secrets Harry's consideration and respect for others extends to the lowly, non-human Dobby and the ghost Nearly Headless Nick. According to Marguerite Krause, achievements in the novel depend more on ingenuity and hard work than on natural talents.
Edward Duffy, an associate professor at Marquette University, says that one of the central characters of Chamber of Secrets is a book, Tom Riddle's enchanted diary, which takes control of Ginny Weasley – just as Riddle planned. Duffy suggests that Rowling intended this as a warning against passively consuming information from sources that have their own agendas. Although Bronwyn Williams and Amy Zenger regard the diary as more like an instant messaging or chat room system, they agree about the dangers of relying too much on the written word, which can camouflage the author, and they highlight a comical example, Lockhart's self-promoting books.
Immorality and the portrayal of authority as negative are significant themes in the novel. Marguerite Krause states that there are few absolute moral rules in Harry Potter's world, for example Harry prefers to tell the truth, but lies whenever he considers it necessary – very like his enemy Draco Malfoy. At the end of Harry Potter and the Chamber of Secrets, Dumbledore retracts his promise to punish Harry, Ron, and Hermione if they break any more school rules – after Professor McGonagall estimates that they have broken over 100 – and lavishly rewards them for ending the threat from the Chamber of Secrets. Krause further states that authority figures and political institutions receive little respect from Rowling. William MacNeil of Griffith University, Queensland, Australia states that the Minister for Magic is presented as a mediocrity. In his article "Harry Potter and the Secular City", Ken Jacobson suggests that the Ministry as a whole is portrayed as a tangle of bureaucratic empires, saying that "Ministry officials busy themselves with minutiae (e.g. standardising cauldron thicknesses) and coin politically correct euphemisms like 'non-magical community' (for Muggles) and 'memory modification' (for magical brainwashing)."
This novel implies that it begins in 1992: the cake for Nearly-Headless Nick's 500th deathday party bears the words "Sir Nicholas De Mimsy Porpington died 31 October 1492".
Chamber of Secrets has many links with the sixth book of the series, Harry Potter and the Half-Blood Prince. In fact, Half-Blood Prince was the working title of Chamber of Secrets and Rowling says she originally intended to present some "crucial pieces of information" in the second book, but ultimately felt that "this information's proper home was book six". Some objects that play significant roles in Half-Blood Prince first appear in Chamber of Secrets: the Hand of Glory and the opal necklace that are on sale in Borgin and Burkes; a Vanishing Cabinet in Hogwarts that is damaged by Peeves the Poltergeist; and Tom Riddle's diary, which is later shown to be a Horcrux. Additionally, these two novels are the ones with the most focus on Harry's relationship with Ginny Weasley.
The film version of Harry Potter and the Chamber of Secrets was released in 2002. Chris Columbus directed the film, and the screenplay was written by Steve Kloves. It became the third film to exceed $600 million in international box office sales, preceded by Titanic, released in 1997, and Harry Potter and the Philosopher's Stone, released in 2001. The film was nominated for a Saturn Award for the Best Fantasy Film, According to Metacritic, the film version of Harry Potter and the Chamber of Secrets received "generally favourable reviews" with an average score of 63%, and another aggregator, Rotten Tomatoes, gave it a score of 82%.
Five unique video games by different developers were released between 2002 and 2003 by Electronic Arts, loosely based on the book: