In the rough years of the revolution in Mexico, the hardened bandit chief, El Chucho, is in need of arms, ammunition, and a much-sought-after machine gun to support the leader of the revolution, the rebel General, Elías. With this in mind, Chucho attacks a government supply train and gets an unforeseen assistance from Bill Tate--the American gringo in the impeccable suit--with whom will soon become friends. Now, Bill is truly indispensable to the gang, however, could he be hiding his true objective behind a boyish and calm face?