Illegal Traffic: G-Man Charles Bent Martin is sent out to break up a nationwide racket. A transport company is aiding fugitives making a getaway in exchange for the lion's share of their loot. Through an old friend, whom he once barnstormed in an air circus, Martin joins the gang as a pilot. He becomes interested in Carol Butler, a beautiful girl involved with the gang through the activities of her ne'er-do-well father.