Three government aviators called the "Flying G-Men", one of whom is disguised as "The Black Falcon", fight to protect the US and its allies from an enemy spy ring and to avenge the death of the fourth Flying G-Man.

Larry Munro has discovered a vein of platinum on his ranch. A group known as the Secret Seven has learned about it and plan to get the Munro Ranch. Kentucky Wade and his friends arrive to help Larry and are soon fighting off attempts on their lives by the henchman of the Secret Seven and the Indians they enlist by bribing them with rifles.

A scientist invents a poison gas; the villain and his gang will do anything to get the formula; our hero, "Lightning Hutch", is sent to save the scientist, the scientist's beautiful daughter, and the formula.

Ken Williams is determined to discover the identity of the mysterious Rattler, who preys upon railroads and transportation companies like that owned by Jane Corwin. The Rattler is especially difficult to catch because of his skill at disguising himself as other people.