Matt Denning (Robert Lansing), a good friend of Emmett Ryker's, believes his younger brother Will (Andrew Prine) innocent of a crime and breaks him out of a military jail where he is awaiting execution, accidentally killing a guard in the process. Along with Matt's wife (Jan Shepard) and son (Kurt Russell), they escape into an area where many Sioux Indians are out for blood, and are trailed by Ryker, army Sgt. Cohane (Myron Healey) and three soldiers. They find the escapees but the party is attacked by the Sioux. Will is killed, confessing as he dies that he was guilty as charged and leading Matt to realize all has been for nothing. Despite the fact the guard's death was clearly an accident, and the fact Emmett and Cohane testify on his behalf, Matt is found guilty and Emmett is forced to uphold the law and turn Matt over to the Sheriff who will escort him to prison.