Britain, 1972. Serena Frome, the beautiful daughter of an Anglican bishop, finds herself being groomed for the intelligence services in her final year at Cambridge. The cultural cold war continues and the country is being torn apart by industrial unrest and terrorism. Serena is sent on a 'secret mission' which brings her into the literary world of Tom Haley, a promising young writer. First she loves his stories, then she begins to love the man. Can she maintain the fiction of her undercover life?