When a down-on-his-luck Vietnam veteran is bludgeoned and stabbed to death in his campsite close to a railroad crossing, Detective Sergeant Bill Palmini has a gut feeling that this is just the tip of the iceberg. Taking command, he swiftly embeds a trusted informant into the shadowy subculture of rail hoppers. What the veteran cop doesn't know, however, is that the murderer is already thousands of miles away and the brutal killing is just one of scores, possibly hundreds, he has committed.