Major guest stars Michael Dunn and Leslie Parrish both had guest starring roles on the original Star Trek (1966) TV series. Dunn appeared in Plato's Stepchildren (1968), and Parrish in Who Mourns for Adonais? (1967). Both episodes had titles and plots concerning ancient Greek culture.
Michael Dunn (Dr. Loveless) and Phoebe Dorin (Antoinette) performed together as a nightclub act in the early 1960's. Favorable reviews in the New York Times and other publications ultimately led to their being cast on the Wild Wild West . Dunn and Dorin appeared together in six episodes of the show.
Dr. Loveless, who would invent a number of fantastic inventions during his run on the show, brags about certain things here. They include the radio, Penicillin (from the bread mold), an automobile, an airplane, and a very powerful explosive, supposedly the same thing that the Professor, whom West was supposed to protect, had also done. They may have been talking about TNT, which was still about two decades into the future of this show's time frame, However Loveless claims his can destroy a city, which sounds more like an atomic bomb.
In order to make it appear that the "Professor" has just been blown up by one of Dr. Loveless' small glass ball explosives the film has been vigorously scratched all around Prof. Neilsen's, as played by Harry Bartell, image for several sequential frames. With the projector light behind it appears that a bright explosion has occurred. This technique can be seen clearly if you freeze-frame at approximately 7:32 where the scratches begin at the upper right corner of Neilsen's head and it stops at 7:33 when the entire frame is white or removed to allow for a bright flash of light just before 7:34.
Five years earlier, Leslie Parrish had worked with Robert Conrad on his previous series Services Rendered (1960).