After the Korean War, Americans Tony (Lemmon) and Felix (Mitchum) own a tramp boat, the "Ruby", which they use for small-scale smuggling around the Caribbean, along with a third crewman, Jimmy Jean (Edric Connor). One day, their bartender contact, Miguel (Anthony Newley), introduces them to an American businessman who has been enjoying the company of beautiful but passport-less European goddess Irena (Hayworth). He has to return to Detroit, but wants to arrange for her to get to another island. They are reluctant, but $1,200 proves very tempting.