At the height of the frontier era, a locomotive races through the Rocky Mountains on a classified mission to a remote Army post. But one by one, the passengers are being murdered! Their only hope is John Deakin (Bronson), a mysterious prisoner-in-transit who must fight for his life--and the lives of everyone on the train--as he uncovers a deadly secret that explodes in a torrent of shocking revelations, explosive brawls and blazing gun battles.