 Complete the following phrase:  The serial contains some similarities with the earlier serial The Vanishing Shadow, such as an invisibility belt and a remote-control robot. Stock footage was used from The Invisible Ray, including scenes of Dr. Zorka finding the meteorite in Africa. As with several Universal serials, some of the stock music came from Frankenstein. The Phantom Creeps car chase was itself used as stock footage in later serials. Newsreel shots of the 