During the Civil War, a Union spy, Andrews, is asked to lead a band of Union soldiers into the South so that they could destroy the railway system. However, things don't go as planned when the conductor of the train that they stole is on to them and is doing everything he can to stop them. Based on a true story.

The arrival in a small mountain town of a dissheveled stranger launches a series of murders committed by some sort of animal. As the town doctor and his daughter attempt to help the stranger, the sheriff investigates the murders; and they uncover a sinister experiment involving two rogue scientists, a car accident victim, his wife and children, and a serum that causes a man to turn into a ravaging werewolf.