Two brothers, on either side of the law, face off over organized crime in Brooklyn during the 1970s.

Pediatrician Dr. Alexandre Beck (François Cluzet) misses his beloved wife Margot Beck (Marie-Josée Croze), who was brutally murdered eight years ago when he was the prime suspect. When two bodies are found near where the corpse of Margot was dumped, the Police re-open the case and Alex becomes suspect again. The mystery increases when Alex receives an e-mail showing Margot older and alive.

The result of the small handkerchiefs "Petits mouchoirs", 7 years later. The band, which erupted, is found on the occasion of the anniversary surprise organized for Max.

Having every reason to be happy, forty-three-year-old father-of-one Guillaume Canet sees his world turn upside down when Camille, his young and fresh co-star, makes him feel like a sad has-been. Now, bent on proving her wrong, insecure Guillaume is eager to go to extreme lengths to change everything and regain his long-lost sex appeal, of course, behind the back of his significant other, Marion Cotillard. However, as the situation spins out of control, a drastic, uncontrollable transformation takes place, much to the horror of the cast and crew. But, above all, Guillaume wants to be cool again. How hard can it be?