
After an attempt is made on the life of bankrupt ranch owner Harl Stoner, the Checkmate agency goes undercover at the ranch's stockholder's meeting, where a ruthless business man sets out to take the ranch and split it up for sale and profit.
A fictional state governor running for re-election stages a phony assassination attempt to boost his chances for victory, and hires Checkmate, ostensibly for protection, but in reality to provide an appearance of credibility. The governor's son is vocal in opposing his father's tactics, but dutifully goes along, mindful of a future political career of his own. Meanwhile, as the campaign winds down, a real threat to the governor's life emerges from within his own campaign.
Luther Gage, an egomaniacal, methodical killer whom Dr. Hyatt helped send to prison, vows revenge and conducts a plot planned to the last detail to carry it out. Checkmate employs the services of Chris Devlin, seen here for the first time, to enter the prison posing as a new inmate to figure out and thwart Gage's plan.