Biker: Bad Road Rising

Josh Pratt is an ex-con turned private investigator. Ginger Munz, a woman dying of cancer hires him to find the son she lost as a baby. The child's father is a sadistic sociopath named Moon who has vowed to kill her, and Josh's girlfriend Cass, for ratting him out. The trail leads to the Sturgis Motorcycle Rally and west into a no-man's land where Josh learns the monstrous fate of the stolen child.