Ian McEwan is back with a masterpiece to equal Atonement, entwining espionage and love in a thrilling new novel. Serena Frome, the beautiful mathematician daughter of an Anglican bishop, has a brief affair with an older man during her final year at Cambridge before taking a job with MI5 in London. The year is 1972: Britain, confronting economic disaster, is being torn apart by industrial unrest and terrorism; the Cold War has entered a moribund phase but the fight goes on and