Is he a girl? Is she a boy? Matthew's American cousin, Sam, has come to London to live with the family. Sam is a charismatic, funny kid, but can he be trusted to be a reliable friend? Matthew and his "mates" decide that Sam must undertake a challenge in order to prove himself: he must start off his new year at their school posing as a girl. It turns out that Sam makes a great girl. He fools everyone and has an electrifying effect at Bradbury Hill School. And the longer the prank goes on, the more hilarious -- and serious -- the repercussions. This brilliant novel shines a laser-sharp beam into the perilous territory of early-teen life, in an unforgettable story of chaos, confusion, and cross-dressing.