United Kingdom, a stylised version of the present. Harry Potter, an adolescent wizard, finds a house elf named Dobby in his Surrey home who warns him not to return to his school Hogwarts. Harry's friends, the Weasley family, rescue him from the house in a flying car.

At Hogwarts an inscription appears in blood one night announcing that the Chamber of Secrets has been opened. Soon staff and students became petrified by unexplained means. Harry and his friends Ron Weasley and Hermione Granger investigate, and learn that the school co-founder Slytherin had a monster sealed up in the chamber a thousand years ago. The chamber has been opened now, as it was a generation ago, by the arrival at the school of Slytherin's direct descendent. Suspicion falls on Harry, especially when he reveals a sinister ability to talk to snakes.

In a remote bathroom the friends meet the ghost Moaning Myrtle, a one-time Hogwarts student. There they cook up a potion to transform themselves into friends of fellow student Draco Malfoy, whom they wrongly suspect of either being or knowing who is Slytherin's heir. Later Hermione is petrified. Harry finds a magic diary of a former student called Tom Riddle. By 'entering' it, Harry learns how the school caretaker Hagrid was accused of opening the Chamber of Secrets when he was a student at Hogwarts and expelled.

In the present, Hagrid is arrested and the headmaster Dumbledore relieved of his post. Harry and Ron discover that the monster Hagrid hid years ago was really a giant spider Aragog who now lives in the woods. Eventually Harry and Ron deduce that Myrtle was killed by the chamber's monster, a massive basilisk (snake). The basilisk has captured Ron's little sister Ginny. Accompanied by conceited but ineffectual Dark Arts teacher Gilderoy Lockhart, they enter the chamber via the bathroom. There Harry meets Tom Riddle, who turns out to be Voldemort, the evil wizard who tried to kill Harry as a baby and is the heir of Slytherin. Harry defeats Voldemort, slays the basilisk and rescues Ginny. The petrified people are restored to normal, Dumbledore reinstated and Hagrid cleared. Harry tricks Dobby's owner, Draco's father Lucius (who planted the diary), into freeing Dobby.

Sight and Sound, January 2003