Tom Hamilton, a young American agent arrives in Nassau in late 1942, when German U-boats are sinking dozens of Allied ships in the Caribbean. Posing as a playboy, his mission is to investigate Nils Ericsson, a Swedish industrialist with ties to the Nazis, whom he suspects is building a case for the U-boat fleet in Hurrican Hole. Hamilton falls in love with a beautiful Englishwoman, Evelyn Shawcross, but with her affiliation to both Ericsson and the Duke of Windsor, wartime Governor of the Bahamas, his operation to foil the plot proves hazardous and deadly.