Deep dislike between 2 main characters - set in north africa expat community

[Mark]

I think the main character is the British consul or something like that. In one of the opening scenes the group go out into the rugged hinterland and have a picnic. This is where the tension between the two protagonists is first shown. I think the main character's wife is seduced by the other man. A third character is a doctor who tries to mediate between the other two.

[Lobstergirl, au gratin]

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