Set in 2068, the series depicts a "war of nerves" between Earth and the Mysterons: a hostile race of Martians with the power to create functioning copies of destroyed people or objects and use them to carry out acts of aggression against humanity.
Communications satellite TVR-17 is destroyed after Captain Black infiltrates ground control and alters the spacecraft's flight path, causing it to prematurely re-enter the atmosphere and blow up.
Back on Cloudbase, the revived Scarlet tells White that he pulled rank on Green to obtain the colonel's whereabouts, used his Spectrum ID to get through navy security and stowed away on the submarine before it left its base.
[8] The scale model representing the USS Panther II was originally made for the Thunderbirds episode "Atlantic Inferno", while the helijet that transfers White to the submarine was first seen in "30 Minutes After Noon".
[10] Chris Drake and Graeme Bassett note the comic depiction of Captain Blue, who makes the most of his stint as commander of Cloudbase by scheduling pointless science lectures and having the Angel squadron conduct unnecessary target practice.
He praises its "well-placed moments of comedy" but argues that the gunfight between Scarlet and the reconstructed Soames underlines the limitations of the puppets, while the "bizarre finale shows that the writers perhaps didn't quite know how to wrap up the story.
"[13] In his review of the Captain Scarlet soundtrack CD, Andrew Pixley of TV Zone magazine names Barry Gray's "White as Snow" as one of two standout tracks.
[14] Andrew Thomas of Dreamwatch magazine believes that Soames' drowning is one of many moments in Captain Scarlet to portray a level of violence that is "graphic, even shocking ... for a children's show".