Dynamite? Blowing up trains? Kidnappers? Seth Dunn could hardly believe his ears. "Yes, " Brigham Young said, "evil man have plotted to blow up the train and kidnap famous people at the Golden Spike ceremony when we complete the railroad at Promontory Point, right here in Utah. I must stop it. Can the Ghost Brigade help?" "Yes sir!" And Seth, Libby, Abe, Hawk, and Jacob plunge into another wild adventure in which they encounter shadowy figures at midnight, nitroglycerin, bats in a deep dark cave, a flash flood, and a murder right before their eyes, as they join hands with Chang, a Chinese youth, Porter Rockwell and Lot Smith, to expose the plot and capture the evil men.