Sean (Channing Tatum) was originally a young man peddling pirated copies on the street, but a street dispute made him get to know two people who changed the course of his destiny. Ticket seller Harvey (Terrence Howard), who also works as an underground boxer agent, takes a fancy to Sean's agility and leads him into the lucrative underground boxing circle. The relationship between single mother Zulai and Sean developed steadily because of a pirated book, but Sean did not know that Zulai and Harvey were inextricably linked. Sean's underground boxer's road is not smooth, in addition to many strong opponents to deal with, the appearance of former boxing team teammate Evan once again uncovered Sean's reluctant to show the gray past, it turned out that Sean's conflict with the coach father forced him to break off the boxer's path. At this time, Harvey, who lived in the same room with Sean, decided to press the dispute for the time being and arranged a boxing match with Evan so that the two could find a new direction.