Ranger Dave Mannion is deprived of his badge for allowing the notorious Braxton gang to drive diseased cattle past his border patrol. He suspects Eric Prang to be a spy for the gang and sets out to prove it.

10 chapter serial wherein a mysterious vigilante known as "The Tiger" steals loot from major criminals, drawing a wide variety of individuals into a fast-paced web of danger and thrills. 1) The Storm Breaks 2) The Tiger's Mark, 3) The Secret Mission, 4) The Danger Trail, 5) The Gas Chamber, 6) Behind the Clock, 7) The Tiger's Claw, 8) Prisoners in the Sky, 9) A Desperate Chance, 10) The Sky Clears.