Harry learns that he is a wizard when he is 11 years old, just before he enrolls in Hogwarts School of Witchcraft and Wizardry. He befriends Ron Weasley and Hermione Granger, and is confronted by Lord Voldemort who is trying to regain power. In Harry's first year he has to protect the Philosopher's Stone from Voldemort and one of his faithful followers at Hogwarts. After returning to the school after summer break, students at Hogwarts are attacked by the legendary monster of the "Chamber of Secrets" after the chamber is opened. Harry ends the attacks by killing a Basilisk and defeating another attempt by Lord Voldemort to return to full strength. The following year, Harry hears that he has been targeted by escaped mass murderer Sirius Black. Despite stringent security measures at Hogwarts, Harry is confronted by Black at the end of his third year of schooling, and Harry learns that Black was framed and is actually Harry's godfather. He also learned that it was his father's old school friend Peter Pettigrew who actually betrayed his parents.