During their travel from Chicago to New York, Harry and Sally debate whether or not sex ruins a friendship between a man and a woman. Eleven years later, and they're still no closer to finding the answer.
A tough police sergeant's mother comes to visit him, and promptly starts trying to fix up his life, much to his embarrassment. For his birthday she buys him a machine gun out of the back of a van, and begins to further interfere with his job and love life, eventually helping him with a case he's on.