When Harry gets to Hogwarts he starts to hear a voice. He hears it first during his detention and second during a party. Students have also been found around the school petrified. Everybody in the school is scared. By doing some research Harry, Ron and Hermione learn that fifty years ago a chamber at Hogwarts was opened by the heir of Slytherin. and a student was killed.
Harry, Ron and Hermione suspect that Draco Malfoy (Their enemy) is the heir of Slytherin. Harry, Ron and Hermione brerw a potion called Polyjuice which allows them to transform into Slytherins for an hour to question Malfoy on the Chamber of Secrets. They find out that Malfoy is not the heir of Slytherin.
Harry finds a diary in a broken toilet in the girls restroom. The diary belongs to a former student, from 50 years ago. Harry writes in the diary, which responds by writing back. Using the diary, Harry meets Tom Riddle.
Hermione and a Ravenclaw girl are petrified. A few days later, Ron and Harry discover a piece of paper with a description of a basilisk on it in Hermione's frozen hand. They assume the Chamber monster is a basilisk. Before the boys can do anything about what they know, the teachers announce that Ginny Weasley has been taken into the chamber.
The boys find the secret entrance to the Chamber of Secrets using Harry’s special gift...