An FBI agent from the East tracks a brilliant but nameless serial killer who has kidnaped his son, the latest move in a vicious game of cat and mouse. From a death-filled room in Amarillo, Texas to a snow-choked train pass through the Rockies, he follows a former railway man and a mysterious young hitchhiker, one of whom may hold the secret of his search. Meanwhile, a local sheriff must chose between winning re-election or helping the agent stay on the trail of the killer.