Onder andere met: Gene Barry (Dr. Clayton Forrester), Ann Robinson (Sylvia Van Buren), Les Tremayne (Maj. Gen. Mann), Robert Cornthwaite (Dr. Pryor (as Bob Cornthwaite)), Sandro Giglio (Dr. Bilderbeck), Lewis Martin (Pastor Dr. Matthew Collins), Houseley Stevenson Jr. (Gen. Mann`s aide), Paul Frees (Radio Reporter), William Phipps (Wash Perry (as Bill Phipps)), Vernon Rich (Col. Ralph Heffner), Henry Brandon (Cop at Crash Site), Jack Kruschen (Salvatore), Cedric Hardwicke (Commentary (voice)), rest of cast listed alphabetically) , (Narrator) Vittorio Cramer ,