Directors: Ford Beebe, Saul A. Goodkind
Cast Bela Lugosi ... Dr. Alex Zorka / Dr. Zane Robert Kent ... Capt. Bob West Dorothy Arnold ... Jean Drew Edwin Stanley ... Dr. Fred Mallory Regis Toomey ... Lt. Jim Daly Jack C. Smith ... Monk Edward Van Sloan ... Jarvis - Spy Chief [Chs. 2-12] Dora Clement ... Ann Zorka [Chs. 1-2] (as Dora Clemant) Anthony Averill ... Rankin - Henchman [Chs. 2-12] Hugh Huntley ... Perkins - Mallory's Lab Assistant [Chs. 2-12] Monte Vandergrift ... Al - Guard [Ch. 5] Frank Mayo ... Train Engineer [Ch. 6] Jim Farley ... Skipper [Ch. 9] Eddie Acuff ... Mac - AMI Agent [Chs. 2-12] Reed Howes ... Signalman [Ch. 10]
Cpt. Bob West is after amoral scientist Dr. Alex Zorka to keep him from selling his fabulous and dangerous discovers to a foreign government, meanwhile Report Jean Drew is looking for a scoop on the same mysterious scientist. Zorka himself is determined to use his discoveries to gain him power and wealth regardless of who he hurts or helps and he has several inventions to help him on his way, including an invisibility harness and a giant robot soldier! Twelve exciting chapters!