Avril Diggory and the Philosopher's Stone

Avril Diggory is starting her first year at Hogwarts School for Witchcraft and Wizardry, her head filled with stories from her older brother Cedric. But when the Sorting Hat begins to cause trouble, a troll mysteriously finds its way into the castle and she finds a three headed dog locked inside the school she becomes rapped up in a race to the Philosopher's Stone.