Harry Potter arrives at the Dursleys under very peculiar circumstances. Although his aunt and uncle aren't at all happy at having Harry live with them, people all over the country are rejoicing at the "boy who lived." Ten difficult years later, Harry begins to get mysterious letters. Despite Uncle Vernon's efforts to keep the letters from him, Harry finally learns that he has been been invited to attend the Hogwarts School of Witchcraft and Wizardry. He also learns that his parents were renowned wizards who were killed by the evil Voldemort. Accompanied by Hagrid, Harry shops for his schoolbooks and materials, including wizard robes, a wand, and an owl. When Harry finally leaves for school, he meets other students, including Ron, Hermione, and Neville, on the train.
At school, Harry meets his new professors, fellow students, and the resident ghosts. He is relieved to be chosen by the sorting hat for Gryffindor, along with Ron and Hermione. At the opening banquet, Dumbledore warns students to stay away from a corridor on the third floor. Harry is disconcerted that so many students seem to know who he is, and he gets the distinct impression that Professor Snape doesn't like him. While rescuing Neville's Remembrall from the bully Malfoy, Harry demonstrates him broomstick skills. As a result, he becomes the seeker on the Gryffindor Quidditch team and even gets a Nimbus 2000 broom. One night he and Ron, Neville, and Hermione accidentally discover a three-headed dog guarding a trap door in the forbidden corridor. Harry is sure the dog is guarding something that Hagrid took from the bank at Gringotts. At Christmas, harry gets an invisibility cloak from an unknown giver. While trying it out, he discovers the Mirror of Erised and sees his family in it.
Harry discovers who Nicholas Flamel is and figures out that the three-headed dog must be guarding the sorcerer's stone. Hagrid breeds a dragon in his hut, which Harry and his friends help send off to Ron's brother in Romania.