Written and produced by Luc Besson, and directed by Louis Leterrier, the action drama headlines international martial arts superstar Jet Li. On and beneath the meanest streets of Glasgow, fiery gangster Bart (Bob Hoskins) is merciless with debtors, would-be rivals and anyone else to whom he takes even a passing dislike. How does Bart maintain his chokehold? Through his unwitting enforcer Danny (Jet Li) who he has "raised" since boyhood. Danny has been kept as a near-prisoner by his "Uncle" Bart; trained to attack and, if necessary, kill. Danny know little of life, except the brutal existence that Bart has so crudely and cruelly fashioned for him.

But when Danny has a chance encounter with soft-spoken blind piano tuner Sam (Academy Award winner Morgan Freeman), he senses true kindness and compassion for the first time and experiences the transforming power of music. When a sudden gangland coup separates Danny from Bart and his mob, Danny is at last away from the underworld. He takes refuge with San and his spunky teenaged stepdaughter Victoria (Kerry Condon). Sam and Victoria open their home and hearts to Danny, who begins to envision a new future for himself. However, the mob will not give up its prize pupil so easily, and Danny must soon fight again, and fight back, to protect his new family and bury his troubled past.