A spoiled and self-absorbed man who has squandered his inheritance, Henry Graham (Walter Matthau) is desperate to find a way to maintain his lavish lifestyle. Henry sees an opportunity when he meets Henrietta Lowell (Elaine May), an awkward and bookish heiress. Though Henry courts Henrietta, he has no intention of remaining with her, and he develops a surprisingly sinister scheme. As Henry attempts to execute his plan, he finds that seeing it through may not be as easy as he had thought.