When her son Henri threatens to go live with his father, Justine improvises with Ludo, her new partner, and her stepson Joseph, a road trip to the Atlantic coast to give her blended family one last chance to unite. The adventure quickly turns into disaster, but also paradoxically awakens the artistic soul of the family. From this chaos a music group is gradually born, The Hennedricks, in which everyone gradually releases their madness. Until allowing this atypical family to finally find harmony?