Middle-aged slumlord Roger (Gourmet) relies on his crafty 15-year-old son, Igor (Renier), to help him do his dirty work in the crumbling tenement where he houses and employs illegal immigrants. During a raid, an African worker falls from a scaffold, and young Igor pledges to take care of the dying man's wife Assita (Ouedraogo) and infant son, who have just arrived penniless from Burkina Faso. Roger panics, though, hiding the body — and the truth — from Assita, leaving Igor torn between loyalty to his father and his own conscience.

Belgian filmmakers Jean-Pierre and Luc Dardenne take on a raft of issues — illegal immigration, poverty, and racism — in this tense, heart-rending moral drama about a lower-class teen's secret effort to usher a vulnerable woman to safety. The gutsy, naturalistic performances of ruffled Renier (star of "L'Enfant") and Gourmet — a burly, slightly menacing actor — raise this movie head and shoulders above most father-son depictions. "La Promesse" offers a raw, devastating vision of grace earned at a heavy price.