Sir Stafford Nye's journey home from Malaya takes an unexpected twist in the passenger lounge at Frankfurt a young woman confides in him that someone is trying to kill her.
Yet their paths are to cross again and again and each time the mystery woman is introduced as a different person. But whichever guise she is in, she draws Sir Stafford into an arena where no-one can be sure of anyone an arena where he must do battle with a well-armed, well-financed, well-trained and invisible enemy