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.

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Main Cast: Bob Steele, Guinn "Big Boy" Williams, Lucile Browne, Jack Mulhall, Purnell Pratt, Robert Frazer, J. Carrol Naish, Bob Kortman, Lafe McKee, Edward Hearn

Directors: Colbert Clark, David Howard

Writers: Barney A. Sarecky, Wyndham Gittens, David Howard, Al Martin, Sherman L. Lowe, Colbert Clark

Editor: Earl Turner

Cinematographers: William Nobles, Alvin Wyckoff, Ernest Miller

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