Harry Potter and the Chamber of Secrets begins when Harry is spending a miserable summer with his only remaining family, the Dursleys. During a dinner party hosted by his uncle and aunt, Harry is visited by Dobby, a house-elf.
Dobby warns Harry not to return to Hogwarts, the magical school for wizards that Harry attended the previous year. Harry politely disregards the warning, and Dobby wreaks havoc in the kitchen, infuriating the Dursleys.
The Dursleys angrily imprison Harry in his room for the rest of the summer. Luckily, Harry's friend Ron Weasley steals Harry away in a flying car, and Harry happily spends the rest of the summer at the Weasley home. ...
Quidditch practices begin and Draco Malfoy is the new Slytherin seeker. On the field, he calls Hermione a "mudblood," insulting her Muggle heritage.
After taunting Hermione, Draco is the suspect when, on Halloween night, someone petrifies the school caretaker's cat and writes a threatening message. Before the cat is attacked, Harry twice hears an eerie voice.
He hears it first during his detention and second during a party, moments before the cat is attacked. Everybody in the school is alarmed.
By doing some research, Harry, Ron, and Hermione learn that fifty years ago a chamber at Hogwarts was opened and a student was killed