二个叛逆小子要合作调查费城最大的犯罪组织，并且把珍贵的美国原住民苏族的古物，重新物归原主。

Léon, the top hit man in New York, has earned a rep as an effective "cleaner". But when his next-door neighbors are wiped out by a loose-cannon DEA agent, he becomes the unwilling custodian of 12-year-old Mathilda. Before long, Mathilda's thoughts turn to revenge, and she considers following in Léon's footsteps.