"I won't spy on Marshal Bulganin," said Troy, "but I will spy on Khrushchev." Khrushchev and Bulganin, leaders of the Soviet Union, are in Britain on an official visit. Chief Inspector Troy is assigned to be Khrushchev's bodyguard and to spy on him. Soon after, a Royal Navy diver is found dead and mutilated beyond recognition in Portsmouth Harbour. What was he doing under the hull of Khrushchev's ship, and who sent him there? Meanwhile, cold-blooded killings have started to follow Troy wherever he goes. Is it possible that the executioner is a fellow policeman, or, worse still, an old friend? In a world where secret codes lead to hidden Swiss bank accounts and an entire nation struggles to makes sense of itself in the wake of war, can anyone be trusted? Inspector Troy's investigation leads him to the rotten heart of MI6 and into the path of an old flame...