In this bitter Comedy of errors (disambiguation), the life of middle-aged bank employee Fabio Bonetti is shaken up by the discovery that, due to a banal swap of identity, a private investigator has followed his wife Lidia (Monica Vitti) for the past five weeks, instead of the rich wife of the landlord, Elena Vitali. While the spectator start to guess that Lidia has something to hide as she is been told what happened-contrarily to Fabio who acts as he barely notices her wife, nor he believe she could actually hold any secrets- the trigger that makes events escalate is the suicide of the landlord, the husband of Elena, after a dramatic phone call with her. This fact will lead Fabio to finally view the filmed material about his wife, in their holiday country house outside Rome. He discovers aspects about his family and his marriage he was not aware of: the heroin addiction of the daughter Veronica; Lidia meeting her assistant and ex-lover Valeria and than cheating on him; himself being deadly ill and with a couple of month left to live- which is later revealed to be another mistake caused by a swap of medical records. All these revelations help him to slowly take his responsibility towards the daughter Veronica and the wife Lidia, becoming an active protagonist in their lives and not only a middle aged bank employee who care more about football matches than cultivate the relationship with his family.