John Whyte, Pinkerton detective, war hero, and banished son of an English Earl, undertakes the difficult assignment of discovering who is responsible for a series of deadly gold shipment robberies. Along with his faithful servant and companion, Kahm Singh, a retired Sikh warrior, and assisted by Curly Bill Williams, a happy-go-lucky Texan, John travels to Denver in the company of Rafe Wallace, the man who hired the Pinkerton's in a desperate attempt to save his gold operations from the vicious gang of cutthroats who seem to know his every plan...