London, Present Day. Callum McGregor is a Nought, a white member of the underclass. Sephy Hadley is a Cross, a member of the black ruling class and daughter of Home Secretary Kamal Hadley. On a night out with his brother Jude, Callum's friend Danny is brutally attacked by two police officers. It's the tenth police brutality this year, and the Noughts are enraged. Sephy falls into danger and Callum needs to save her - but she makes a terrible mistake and must make it up to him somehow. Meanwhile, Nought agitator Jack Dorn exploits the growing unrest for his own gains and takes matters into his own hands.