 In 1980, the episode was re-edited for inclusion in the "Captain Scarlet" compilation film "Captain Scarlet vs. the Mysterons".In 2068, the crew of the "Zero-X" spacecraft land on the surface of Mars in the Martian Exploration Vehicle (MEV) to locate the source of unidentified radio signals detected by the Spectrum security organisation on Earth.The source is revealed to be an alien city inhabited by the Mysterons (voiced by Donald Gray), a collective artificial intelligence with powers over matter.