The Tamarind Seed (1974)

Widowed when her husband was killed in a car accident three years ago, Judith Farrow, who works in the Home Office in London as the assistant to Sam Neilson, embarks in an affair with Paris-based married RAF group captain Richard Paterson. Breaking it off with Paterson when she discovers that he is not only not going to leave his wife Rachel as he said he would, but that he is staying with her upon news that Rachel is pregnant, Judith, to nurse her emotional wounds, is granted an early two-week vacation which she takes in Barbados. There, she meets similarly vacationing Feodor Sverdlov, a Soviet military attaché currently assigned to the embassy in Paris. Despite being married himself with his wife still back in the Soviet Union, Sverdlov pursues Judith romantically. This situation is not lost on either the British or Soviets. With Sverdlov long having been on his radar, Jack Loder with the British Secret Service, is concerned they vacationing in Barbados is not coincidental as he knows that Judith would be an asset to the Soviets in Neilson having enough valuable information to the enemies, and she easily getting back into a relationship with Paterson if requested to do so by the Soviets. Loder is already having to deal with some extramarital affairs within the British diplomatic corps which have the potential to upset the apple cart, but arguably more problematic that there is a possible double agent in their midst working for the Soviets, hence the reason why Sverdlov has been on his radar. General Golitsyn, heading the Soviet Embassy in Paris, also believes that Judith would be a good asset for them if Sverdlov is able to recruit her. Judith and Sverdlov are quite aware of how their personal relationship looks to their proverbial professional masters and as such are constantly being surveilled on both sides, but the question remains if they both vacationing in Barbados at the same time was indeed not coincidental.