A mysterious rash of cargo ship sinkings in Panama leads insurers Llewellyns of London to hire vacationer Nick Carter and his eccentric associate Bartholomew to investigate. Nick recognizes influential nightclub owner Al Taurez as a shady operator, but getting the goods on him depends on slick diversions involving the heavyweight champ of the Pacific Tuna Fleet, a Panamanian bombshell armed with American slang, a young couple in love and a whole raft of crooks and cutthroats.