Raised as a slave, Danny is used to fighting for his survival. In fact, his "master," Bart, thinks of him as a pet and goes as far as leashing him with a collar so they can make money in fight clubs, where Danny is the main contender. When Bart's crew is in a car accident, Danny escapes and meets a blind, kindhearted piano tuner who takes him in and uses music to free the fighter's long-buried heart.

The film takes place in Paris, where two cops are competing for the vacant seat of chief of police while in the middle of a search for a gang of violent thieves. The movie is directed by Olivier Marchal, a former police officer who spent 12 years with the French police before creating this story, which is taken in part from real facts that happened during the 1980s in France.