Guillaume Canet is told by a young co-star that he's no longer Rock'n' Roll and can't sell films anymore. He then tries to prove her wrong and gets help from his girlfriend, Marion Cotillard.

A bourgeois office drone whose raison d'être is the music of French rocker Johnny Hallyday awakens one day in an alternate universe where the famed musician never recorded a single song. When he’s not at the office dutifully plugging-away, Fabrice lives a deadly dull life.