Fighting master Bourne (Michael Jai White) was recently released from prison. He rented a room in a hot and somewhat chaotic neighborhood in Los Angeles. Every night when the night falls, countless underground boxing rings in the city also become active. Bourne quickly found a black boxing agent Ping Bao, and after cooperating with him, he defeated countless opponents. The purpose of this series of battles is to obtain the qualification to challenge James's gang. James has the most powerful black boxing fighters in his hands, and his lover Angela seems to have a close relationship with Bourne... Soon, Bourne successfully defeated James' fighters. James was impressed by Bourne's strength and invited him to participate in the international underground fighting competition that could bring huge benefits. Bourne was not moved because his purpose of fighting on the streets was far from being as simple as money.