To rob mail transport planes, Dawson (Walter Miller) and his gang of criminals kidnap Prof. Brent (Lloyd Ingraham), the inventor of a powerful ray gun. When planes begin crashing mysteriously, federal agent Tim Caverly (Tim McCoy) investigates the case and tries to infiltrate Dawson's gang. In search of her father and hoping to prevent more airplane disasters, Brent's beautiful daughter, Natalie (Claudia Dell), also arrives on the scene.