Many people have deep yearnings for a romantic life of passion, intimacy, danger, and adventure. Silvio Soldini is a talented Italian director who has described this turf before in the wonderful film Bread and Tulips where a 49-year-old housewife leaves her husband and family behind during a bus tour of Europe; she follows her heart to Venice and like the heroine in Shirley Valentine, finds an undiscovered and unused part of herself in a strange city. Soldini is a masterful mood maker able to draw out the emotions which both challenge and hinder married couples. In Days and Clouds, a couple's relationship is torn asunder when he loses his job. In Come Undone, the director probes the powerful emotions which lie behind adultery and the challenges and roadblocks faced by those who give in to their sexual desires.

Anna (Alba Rohrwacher) is married to Alessia (Giuseppe Battiston). They have a relaxed relationship that both of them take for granted. She has a job at an insurance agency, and her boss has great respect for her attention to details and relies upon her memory to help him in times of stress. Her best friend is a co-worker who seems to understand and appreciate her more than her own sister and mother.

When Anna meets Domenico (Pier Francesco Favino), a swarthy waiter, the comforts and companionship of her cozy relationship are superceded by the thrills of raw sex. He is a married man with two small children and a job that does not pay him enough money to take care of his family. His wife (Teresa Saponangelo) has her hands full raising the young ones.

At first he shies away from an affair but then capitulates to his libido. Anna and Domenico soon find themselves caught up in brief secret encounters, a web of lies that keeps expanding, feelings of guilt, and disappointment that things do not pan out as they hoped they would. This anatomy of a sexual affair by Silvio Soldini vividly conveys both the erotic ecstasies and the staggering burdens and familial responsibilities which make it nearly impossible to stay in the present moment.