1956. The Cold War cracks a little. Nikita Khrushchev, the most powerful man alive, is visiting London, and Russian emigre Chief Inspector Troy is assigned to protect him. A whistle-stop tour, a clandestine trek to an East End pub, and a murder, provide Troy with excitement enough. But when the body of a retired Royal Navy diver is found floating near a Russian battleship in Portsmouth, it gives every excuse for both sides to refreeze the Cold War. Troys investigation leads him to the rotten heart of M16 and into the path of an old flame - Larissa Tosca, late of the US army, later still of the KGB...