The strapping Tom Tyler, in his fourth and last serial for Universal, played a daredevil pilot coming to the aid of a beleaguered scientist (William Desmond). In between romancing the professor's lovely daughter (Gloria Shea), Tyler battles a series of villains out to steal the "Contragrav," an anti-gravity device. The always suspicious-looking Leroy Mason is the head of a gang of smugglers that include such well-known blackhearts as Edmund Cobb, Bud Osborne, and Wheeler Oakman. A youngish Walter Brennan offers mild comedy relief, while Hugh Enfield played one of Tyler's pilot friends. Enfield later briefly changed his billing to "Robert Allen" before settling permanently on the moniker Craig Reynolds.