Mark Burgess has hit puberty with gusto - surly, smelly but somehow gorgeous, he is the epitome of cool at school. Then disasters strikes! An apparition appears behind him in the mirror - it's Mark Two, his perfectly groomed, goody-goody Doppelganger!
The only other person who knows is Mark's best friend, Whittaker. While Mark lingers miserably in his bedroom surrounded by dead pizzas, Whittaker updates him on Mark Two's increasing popularity with his mum, his girlfriends and his teachers. Somehow, they have to get rid of him before he destroys Mark's reputation forever.