Page "Captain Scarlet and the Mysterons" Paragraph 8

While Scarlet and Spectrum defend Earth against the threat from Mars, it is found that Mysteron reconstructions are particularly vulnerable to electricity and that they are detectable on X-rays, to which their biology is impervious.

Consequently, two anti-Mysteron devices, the " Mysteron Gun " and the " Mysteron Detector ," are developed to aid Spectrum.

A three-episode story arc charts the uncovering of a second Mysteron complex under construction on the Moon, its destruction by Spectrum, and efforts to negotiate with the Mysterons on Mars via a crystal power source, salvaged from the complex, which is converted into an interplanetary communication device.

A failed attempt at satellite surveillance of the Martian surface, aborted military conferences and the sabotaged construction of a new space fleet hinder Spectrum's plans to return to Mars, and the organisation is unsuccessful on two occasions in apprehending Captain Black.

The penultimate episode of the series depicts a Mysteron assault on Cloudbase with the use of armed spacecraft, which is ultimately revealed to be a nightmare dreamt by one of the Angel pilots.

The finale is a flashback episode that ends inconclusively with regards to the war between Earth and Mars and the fate of Spectrum and the Mysterons.