The Mystery Squadron

Hank Davis, foreman on a huge dam project, enlists the aid of his two flyer friends when a sinister figure known as The Black Ace leads his Mystery Squadron of masked pilots in an attempt to destroy the dam.

• Director: Colbert Clark
• Cast: Bob Steele, Guinn 'Big Boy' Williams, Lucile Browne, Jack Mulhall, Purnell Pratt, Robert Frazer, J. Carrol Naish, Bob Kortman