Captain Jay Fuller is a United States Cavalry officer who is called in to lead a counter-attack on Commanche settlements. Believing that the Commanche are truly responsible for the destruction of white settlements, Captain Fuller and his men deal back "tenfold" violence. Fuller shows a tinge of regret when he learns that the Commanche were not responsible, but he is persuaded to side with Latham Cole and Butch Cavendish when Cole threatens to accuse him of the war crime of slaughtering innocents.
Captain Fuller, along with Latham Cole and Butch Cavendish, attempted to stop Tonto and Reid when they interrupted the railroad unification ceremony by stealing one of the trains. He is outwitted by Tonto and knocked unconscious, regaining his senses just in time to leap from the train, which Tonto and Reid had manipulated to collide with Butch Cavendish in another car.