London, the week before Christmas, 2007. Over seven days we follow the lives of seven major characters: a hedge fund manager trying to bring off the biggest trade of his career; a professional footballer recently arrived from Poland; a young lawyer with little work and too much time to speculate; a student who has been led astray by Islamist theory; a hack book-reviewer; a schoolboy hooked on skunk and reality TV; and a Tube train driver whose Circle Line train joins these and countless other lives together in a daily loop.