The Contractor is based upon an actual event, an 1868 murder in a railroad camp during the building of the Union Pacific. The killer, a construction contractor, flees the territory only to find himself being pursued by N.K. Boswell of the Rocky Mountain Detective Agency. When Boswell takes the murderer into custody, however, the detective finds that his problems have only just begun. Now he has to transport him back to Laramie. Forty miles of empty Iowa prairie, then the flooded Missouri River, then four hundred more miles of prairie. And all the while the murderer's brother and his gang of thugs are determined to stop Boswell at any cost.