John Agar (Dr. Matt Hastings), Mara Corday (Stephanie 'Steve' Clayton), Leo G. Carroll (Prof. Gerald Deemer), Nestor Paiva (Sheriff Jack Andrews), Ross Elliott (Joe Burch), Edwin Rand (Lt. John Nolan), Raymond Bailey (Townsend), Hank Patterson (Josh), Bert Holland (Barney Russell), Steve Darrell (Andy Anderson), Tom London (Jeff), Clint Eastwood (Düsenjägerpilot), Eddie Parker (Paul Lund), Don Dillaway (Jim Bagny), Ray Quinn (Staatspolizist), Bob Nelson (Staatspolizist), Bing Russell (Deputy), Billy Wayne (Murphy), Dee Carroll (Telefonist), Rusty Wescoatt (Fahrer), Jack Stoney (Helfer), Bud Wolfe (Busfahrer), Robert R. Stephenson (Lagerarbeiter), Stuart Wade (Major), James Hyland (Trooper Grayson), Jane Howard (Sekretärin), Edgar Dearing (zweiter Tramp), Vernon Rich (Ridley), Paul Lund (Eddie Parker)