A boxer knows how to get back up when knocked down. So when life spins out for French bare-knuckle fighter Ali (Matthias Schoenaerts), he spends his last euros on a train out of town, his 5-year-old son in tow. It's a responsibility this sullen brute of a man barely knows how to deal with, but he does his best, crashing at his sister's garage in the seaside town of Antibes and finding work as a bouncer at a local nightclub.

One night he helps (and hits on) a young woman, Stéphanie (Marion Cotillard), who's been knocked flat in a fight. The first glimpse we get of her is her long bare legs as she lies on the ground. Take a good look: They won't be there for long. Shortly after their brief meeting, Stéphanie — an aquarium trainer of orca whales — has both legs amputated below the knee after a horrific accident.

She despairs. Her career is gone, as is her less-than-committed boyfriend. For reasons she's not even sure of, she calls Ali. He meets her for coffee, and in his gruff, take-it-or-leave-it way, asks her: "You wanna go swimming?" Stéphanie thinks he's crazy, but he just shrugs and heads down to the beach.