John Drake is assigned to investigate the murder of a banker, Frank Delroy. The trail leads Drake to the home of Delroy's lady friend, a small seaside resort (Portmeirion) where he recovers five million dollars and solves the murder of Delroy.

Drake's assignment is to find a double for James Carpenter, an American who is confined to the US Embassy in a Caribbean city. Finding the double is only half of the problem. Substituting him under the eyes of the police is the other.

Drake travels to Kashmir in Northern India to seek out Noel Goddard, a former executive in the Indian Government, now a traitor. On identifying Drake, Goddard is given the message: 'John Drake. NATO agent. Eliminate.'

When several workers at an atomic energy plant in North Africa fall ill, a leakage is suspected. Drake flies out to investigate and is aided by a beautiful European doctor, but when the next victim has no connection with the plant, Drake discovers a fiendish plot.