The first scene of Captain Scarlet and the Mysterons is also one of the show’s most memorable, showing the Zero-X MEV under the command of Spectrum’s Captain Black discovering the Mysteron city and subsequently destroying it after mistaking a scanning device for a weapon. This launches the war between the Earth and Mars, and is also the moment where Captain Black falls under Mysteron control. However, one question still lingers around this scene; whatever happened to Lieutenant Dean and navigator Conway, the two men who accompanied Black to the Mysteron city and were then never seen again?
Given what we see in Thunderbirds are Go we can assume that at least one other member of the team was left behind on the main body of Zero-X, which remained in orbit of Mars until the return of the MEV, giving us three or more men missing in action (aside from Captain Black) following this mission. All we can be certain of based on dialogue heard in the first episode of the television series is that Captain Black “disappeared on his return” from Mars, indicating that Zero-X did indeed return to Earth in a way that Spectrum were aware of and that Black wasn’t simply teleported from one planet to the other. The mini-album Introducing Captain Scarlet confirms this to be the case, as Colonel White claims that radio contact between Earth and the MEV was cut off immediately following the destruction of the Mysteron complex. “We knew nothing more until the expedition craft with only Captain Black aboard returned to Glenn Field,” he adds, suggesting that no trace was ever found of the Zero-X crew. Presumably had their bodies been anywhere on the Zero-X they would have been found during the subsequent investigation that most likely took place, based on Captain Blue’s later mention of a recovered film recording of the Mysteron city taken by the MEV crew in the episode Lunarville 7 (which may also explain how Colonel White could recall Black’s initial attack on it so accurately in Dangerous Rendezvous).
Although Zero-X’s return from Mars wasn’t depicted on television, it did make the pages of the TV21 comic via the strip story Front Page. Issue 139’s instalment of Front Page saw the intrepid reporter Pete Tracker and his photographer Lens trying to get the scoop on a mysterious floating aircraft carrier (soon to be revealed as Cloudbase), only to find themselves on a collision course with the Zero-X as it made its final return approach to Glenn Field following Captain Black’s mission to Mars. Colliding with the Zero-X at the beginning of issue 140’s episode, their subsequent crash landing allowed Black time to escape from the base in the confusion – thus providing a plausible explanation for how he managed to evade Spectrum. It also loosely ties in with White’s dialogue in Introducing Captain Scarlet; “before we could question him, he disappeared.”
All this gives us a credible account of Black’s arrival back on Earth, but sadly nothing to indicate the fate of the Zero-X crew one way or another – beyond the fact that they didn’t return to Earth with their ship. It is most likely that they were either left behind on Mars (perhaps to be studied?) or killed by Black shortly after he fell under Mysteron control and their bodies dumped in space. The possibility exists that they too could have been Mysteronised and returned to Earth to act as agents, although given that the Mysterons tell them “one of you will be under our control” and that that “one” was obviously Black it would seem unlikely. Since even Gerry and Sylvia Anderson’s original script for the first episode of Captain Scarlet also provides no explanation of the fate of Dean and Conway, it would seem to be entirely down to the viewer to decide for themselves what may have happened to them – but we can safely assume it probably wasn’t anything pleasant!