A former member of the van der Linde gang of outlaws, John Marston is being blackmailed by government lawmen to hunt down his former partners-in-crime. Driven further into the American Southwest, Marston soon finds that Williams has crossed into Mexico, a country in the throes of a civil war. At every turn, Marston must choose whether to side with outlaws, lawmen, rebels, or innocents in the crossfire.