<P> Just as Harry is starting to anticipate his return to Hogwarts, 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 Defence Against the Dark Arts professor after the death of Professor Quirrel . 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 pass, forcing them to fly Arthur's car to the school, where they crash into a sentient willow tree on the grounds . </P> <P> 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 celebrity teacher 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 deathday party for the ghost of Gryffindor House, Nearly Headless Nick, 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 ." </P> <P> 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 . </P> <P> 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 . </P>

Who tells harry about the chamber of secrets