About to enter his second year at Hogwarts School of Witchcraft and Wizardry, Harry Potter is visited by a house-elf named Dobby and warned not to return. Harry ignores his warning and returns to Hogwarts, where strange things begin to happen, as people are becoming petrified, Harry hears a voice which seems to be coming from within the walls, and Harry's newly-discovered and unsettling ability to communicate with snakes turns even his friends against him.
