Former U.S. Army major Paul Krenner (James Griffith) plans to conquer the world with an army of invisible soldiers and will do anything to achieve that goal. With the help of his hired muscle, Julian (Red Morgan), Krenner forces Dr. Peter Ulof (Ivan Trisault) to perfect the invisibility machine Ulof invented. He keeps Ulof's daughter, Maria (Carmel Daniel), imprisoned to keep Ulof in line.