After a particularly horrible summer at home with the Dursleys, Harry can’t wait to return to Hogwarts for his second year. Banished to his bedroom, Harry receives a visit from an elf named Dobby, who warns him that he must not return to the school, for great danger awaits him there. Finally, he is rescued from his bedroom prison by Ron and his brothers in their flying car. Despite Dobby’s warnings, Harry returns to Hogwarts and stumbles right into the mystery of the Chamber of Secrets.
On Halloween night, Harry, Ron and Hermione find a message painted on a wall that reads, “The Chamber of Secrets has been opened. Enemies of the Heir, beware.” They soon discover that the Chamber of Secrets contains a deadly monster, that it hasn’t been opened for 50 years, and that the last time it was opened, someone died. “The heir” in the message refers to a descendant of one of the school’s four founders, Salazar Slytherin, who had an affinity for the dark side of magic.
The three friends eventually go to the Chamber and fight the creature.

Author: J.K Rowling