U.S. Marshals Lincoln Hawk and Stewart Montague were pursuing Colm Tobin's train-raiding gang of bandits when Stewart goes missing, presumed dead. For six months Lincoln continues the mission alone without success while Colm escalates his reign of terror, culminating in his most audacious crime yet of spiriting away a whole train.

Facing increasing pressure to bring the bandits to justice, Lincoln foils what looks like another raid with deadly gunfire, but although one of the suspects was the last man to see Stewart alive, the dead men were innocent. His mistake threatening to end his career, and with everyone turning against him, how will Lincoln restore the honor of the badge?