This story debuted with either the Second or Third Doctor, then was reprinted with the Fourth Doctor. It may have had different companions in the reprint, as well. From an in-universe point of view, it's unclear which Doctor lived through these events.
Doomcloud was notable for being the comic strip debut — along with the simultaneously-published Perils of Paris — of Sarah Jane Smith. Though it was not a part of the regular run of TV Comic stories, it nevertheless represented the return of televised companions to Polystyle comics — something that hadn't been the case since 1970. It also featured the return of UNIT, an organisation that had also been abandoned by Polystyle around the same time.
About four years after its 1974 publication, it became the first "recycled" Polystyle comic; as the original artist's work was retouched by John Canning so that the Third Doctor was replaced by the Fourth Doctor. Perhaps because Elisabeth Sladen had left the programme by the time of the Fourth Doctor version, Sarah Jane was replaced in the remix by Joan Brown, a character different in name only.
The Third Doctor and new friend Sarah Jane Smith arrive on Earth to find the planet facing its greatest threat. Can the Doctor save Earth from a deadly virus? Just what are the creatures declaring genocide upon humanity?
to be added
- For the Fourth Doctor remix, Sarah became "Joan Brown", but the artwork was left unchanged. The Brigadier, meanwhile, had his moustache removed and glasses added — transforming him into General Maxwell-Lennon.
- In the Fourth Doctor version, the re-letterer fails to change one of the references to Joan. In a way that would have made no sense to readers at the time, the Doctor calls Joan "Sarah" in one panel.
- The Doctor takes Sarah/Joan to watch a dying planet. The Ninth Doctor would later take Rose Tyler to watch the death of the Earth. (TV: The End of the World)