A British archaeologist finds himself entangled in a dangerous conspiracy involving a mysterious caravan moving through the Camargue region of France. Neil Bowman, an agent for the British Secret Service, assumes the identity of an archaeologist to investigate reports of a secret, high-stakes operation occurring in the remote marshes. He must navigate a landscape of shifting loyalties and hidden agendas while attempting to uncover the true nature of the caravan's cargo. The narrative unfolds with a focus on tactical maneuvering and the tension inherent in maintaining a false identity under constant surveillance.

This novel is often regarded as a departure from the author's more conventional high-octane action thrillers, favoring a slower, more atmospheric build. The setting of the Camargue provides a distinct backdrop that distinguishes the work from typical espionage fiction of the period. Readers often note the technical focus on the protagonist's investigative methods, which reflects the author's signature style of placing capable men in complex, isolated environments. The narrative structure relies heavily on the tension of the protagonist's dual identity, creating a methodical experience that prioritizes suspense over explosive set pieces.