Joe Clay, played by Jack Lemmon, meets Kirsten Arnesen, played by Lee Remick, in a professional setting and eventually falls in love with her. After they get married, Joe introduces Kirsten to drinking, initially as a way to cope with his own stress, but she soon develops an addiction. As their lives spiral out of control due to alcoholism, Joe realizes he needs help and finds support through Alcoholics Anonymous, while Kirsten's struggles continue, leading to a heartbreaking confrontation between the couple about their future together.