Colin and Maria are on vacation in Italy. they are lovers but as their holiday unfolds they are increasingly bored and uninterested in each other. They amble around hotels and tourist streets without any real interest. When they meet Robert and his crippled wife Caroline who have a disturbing story to tell they discover their physical attraction to one another. But they also feel increasingly uneasy with the friendship of this odd couple and become drawn into a fantasy of violence and obsession.