Directors: Colbert Clark & David Howard
Cast: Bob Steele ... Fred Cromwell ‘Big Boy' Williams ... 'Jellybean' Cook Lucile Browne ... Dorothy Gray Jack Mulhall ... Henry 'Hank' Davis Purnell Pratt ... Lafe Johnson Robert Frazer ... Dr. Flint J. Carrol Naish ... Collins Bob Kortman ... Bracken Lafe McKee ... Stephen Gray Edward Hearn ... Sheriff Kernan Cripps ... Tom - Dam Foreman Edward Peil Sr. ... Andrew Martin Jack Mower ... Carter - Henchman Jack Perrin ... Roberts - Mystery Flyer
Danger, mystery and lots of aerial thrills in this twelve chapter Mascot serial!
A group of flyers, known as The Mystery Squadron, are menacing the workers on a new dam. Their leader, The Black Ace, promising harm unless all work ceases. So engineer Henry Davis hires his friends, the best flyers he knows, Fred Cromwell and Jellybean Cook to run down the Mystery Squadron and unmask The Black Ace!