Arthur Dreyfus and César Montesiho are two different men and two lifelong friends from the school times: while Arthur is a neurotic chemical teacher in a university hospital divorced of his wife Virginie and with a stranded relation with his teen daughter Julie, César is a free-spirited bohemian and womanizer always on money troubles, with Lucia as his last conquer. After an accidental fall from his balcony when a pawnbroker went to his house claiming his belongings by not paying the loan he has, César meets Arthur asking some of money. Learning that César is hurt in his back, Arthur forces César for going to the hospital to heal him, but a few days later Arthur is called by a doctor's hospital to give him bad news: a radiography revealed a terminal lung cancer with a six-months lifespan. Shocked and confused by it, Arthur meets César attempting to tell it, but César's revelation about an incoming paternity with Lucia causes a huge misunderstanding, with César thinking by mistake that he's Arthur the ill. ...