Twelve-year-old Mack McAvoy's life is about as boring as you can get, until a 3,000 year old man appears in the boy's bathroom at school with a life-changing story. Mack is one of the Magnificent Twelve, a group of twelve 12-year-old heroes destined to fight the Pale Witch and the other evils threatening earth. But the Pale Witch and her daughter, Ereskigal, sound scary, and Mack doesn't want to be a hero. Will he answer the call?