Clean-cut ladies man Tony (Jack Lemmon) and former rummy Felix (Robert Mitchum) are co-owners of a dicey tramp-steamer service based on the island of San Juan. A nervous American businessman (Lionel Murton) pays them to take the mysterious world-weary bad girl Irena (Rita Hayworth) to a neighboring French West Indies island on the secret, because she has no valid papers. The sexy femme fatale, who says such laughable things in such a serious tone as “Armies in Berlin have marched all over me,” stirs both men up with her hot body. This causes a jealous misogynistic Felix to play dirty with his partner-friend when the tramp chooses to marry Tony. Both agree to dissolve the partnership and sell the boat, but Tony proposes that they smuggle one last shipment of contraband before splitting the profits. Felix cautions him not to marry Irena and when not listened to, tells him to take the boat without him. During Tony’s smuggling trip, a Coast Guard cruiser suddenly appears and Tony and his loyal mate Jimmy Jean (Edric Conner) jump overboard to avoid arrest and swim safely to shore. The vengeful Tony, certain that Felix betrayed him and packing a gun, signs on as a crew-member aboard a Greek freighter. But, if you will, the freighter collides with an ocean liner near the dock and Tony is the only sailor trapped below deck unable to be freed by the U.S. Navy and unwilling to have Dr. Sam (Bernard Lee), the port’s physician, amputate his legs to free him. Time begins running out before the freighter, which has a fire aboard that can’t be extinguished, and Tony is uncommunicative about what to do except refusing amputation. Felix and Irena are called in to talk some sense into the lad. In Tony’s absence, Irena and Felix came together knowing they were meant for each other: being jaded types who have betrayed many others and understand each other only too well.