During the 1920s, the "Mann Act" Prohibited transporting a woman across state lines for "immoral purposes". Therefore, Nick (Warren Beatty), eager to run off to California with his sweetheart Freddie (Stockard Channing), arranges for her to marry his friend Oscar (Jack Nicholson) until his divorce is final. Oscar agrees, banking on the notion that marriage to an heiress could only prove financially rewarding. However, nobody bargained for love and lust to turn this simple business arrangement into a confused lovers' triangle! Ultimately, the only way Oscar and Nick can expect to benefit from Freddie's wealth without killing each other is to kill her and split the inheritance fifty-fifty. But will their desire for her fortune overcome their affection for Freddie herself?