When feisty teenaged thief Kat's on-again off-again boyfriend, Hale, suddenly inherits his family's billion dollar company, Kat gets a tip-off that the will is a fake.

Fifteen-year-old Kat schemes her way into the best boarding school, hoping to leave the thieving antics of her family behind her, but Hal, a former co-conspirator, appears on campus to tell Kat that a powerful mobster believes her father stole art from a priceless collection, and in order to save him, Kat will have to recover the paintings.

In Victorian London, a boy known as Joe Rat scrounges for valuables which he gives to "Mother," a criminal mastermind who considers him a favorite, but a chance meeting with a runaway girl and "the Madman" transforms all their lives.