The Saint and Patricia go to visit some friends in Miami - but when they get there they are shocked to learn their friends have disappeared. They move into their friends' house and start to investigate. Things get complicated when a tanker explodes off the Florida coast and a dead British sailor washes up on the shore. Simon suspects a link between the explosion and the disappearance, as well as the activities of shady millionaire Randolph March. There seems to be a Nazi spy ring operating out of Florida...