Baaba Keita (Sy) has built his whole life in the working-class Paris neighborhood of Belleville, where his beloved mother reigns as queen. As a cop, he's refused all promotions in order to stay there. Even his girlfriend is tired of watching him getting nowhere.
When his childhood friend Roland comes to visit from Miami to warn him about the drug trade taking over their neighborhood, Baaba wants to find out more, but his buddy gets killed before he can say anything else. To avenge his friend, Baaba packs his things and his mother and moves to Miami.
In order to see his investigation through to the end, he teams up with an American cop, Ricardo (Guzman), who doesn't like the fact that Baaba doesn't go by the book.