Patsy Newquist (Marcia Rodd) is a 27-year-old interior designer who lives in a New York rife with street crime, noise, obscene phone calls, power blackouts and unsolved homicides. When she sees a defenseless man being attacked by street thugs, she intervenes, but is surprised when the passive victim doesn't even bother to thank her. She ends up attracted to the man, Alfred Chamberlain (Elliott Gould), a photographer, but finds that he is emotionally vacant, barely able to feel pain or pleasure. He permits muggers to beat him up until they get tired and go away.
Patsy is accustomed to molding men into doing her bidding. Alfred is different. When she brings him home to meet her parents and brother, he is almost non-verbal, except to tell her that he doesn't care for families. He learns that Patsy had another brother who was murdered for no known reason. Patsy's eccentric family is surprised when she announces their intention to wed, then amazed when their marriage ceremony conducted by the atheistic Rev. Dupas (Donald Sutherland) turns into a free-for-all.
Determined to discover why her new husband is the way he is, Patsy coaxes Alfred into traveling to Chicago to visit his parents. He hasn't seen them since he was 17, but asks them to help with a questionnaire about his childhood at Patsy's request.
Alfred ultimately agrees to try to become Patsy's kind of man, the kind willing to "fight back". The instant that happens, a sniper's bullet kills Patsy, again for no apparent reason. A blood-splattered Alfred goes to her parents' apartment, New Yorkers barely noticing his state. He descends into a silent stupor, Patsy's father (Vincent Gardenia) even having to feed him.
A ranting, disturbed police detective, Lt. Practice (Alan Arkin), drops by, almost unable to function due to the number of unsolved murders in the city. After he leaves, Alfred goes for a walk in the park. He returns with a rifle, which he doesn't know how to load. Patsy's father shows him how. Then the two of them, along with Patsy's brother (Jon Korkes), take turns shooting people down on the street.