Tom Ripley (Alain Delon) travels to Italy to visit his playboy friend Phillippe Greenleaf (Maurice Ronet) and Phillippe's new fiancée, Marge Duval (Marie Laforêt). What Phillippe doesn't know is that his father has paid Tom to convince his son to abandon Europe and return to his family responsibilities in San Francisco. But when Phillippe's family cuts off their funding of Tom's extravagant lifestyle during his covert mission, he discovers another way to maintain his newfound standard of living.