 Playboy Henry Graham (Walter Matthau) squanders his wealth and must seek out a new source to maintain his idle rich lifestyle. The easy alternative to work is to find a rich woman, marry her, and murder her. Klutzy, nerdy Henrietta Lowell (Elaine May) is the ideal candidate. But in dealing with his klutzy, nerdy, trusting new wife, a botanist, and her ill-managed estate, Henry unwittingly begins to assume some sense of responsibility, not realizing this while planning to do away with Henrietta on one droll camping trip...