With both Paraguay and Argentina under junta governments, doctor "Eduardo" (Richard Gere) returns to his homeland where he quickly befriends the eponymous gent "Fortnum" (Michael Caine) before making even closer friends with his somewhat open-minded wife "Clara" (Elpidia Carrillo). Ostensibly an upstanding member of the community it soon becomes clear that this physician is conflicted, and that comes to an head when his dipso friend is charged with driving the US Ambassador to visit a waterfall. The rebels get wind of this trip and plan to kidnap the visiting diplomat, but they get the wrong ma...