For such an iconic serial there’s not an awful lot of story here: the Doctor continues to share fragments of a backstory he already knows, while we’re left to try to piece together the bigger picture, but the essentials boil down to Sutekh ‘destroyed his own planet, Phaester Osiris, and left a trail of havoc across half the galaxy. Horus and the rest of the Osirans must have finally cornered him on Earth.’ In some respects this is Pertwee-style ancient gods stuff, but that just makes the differences even more marked. This is nothing like the sugar-rush whimsy of The Time Monster, and is more macabre than The Dæmons. Instead of big-budget Action by HAVOC the show’s now spending its (presumably smaller, thanks to 1970s inflation) budget on impressively detailed sets, and aiming for creeping dread.

I’d characterise the difference that The Dæmons was science fiction with horror overtones and this is horror with science fiction overtones. Everything has a superficially rational explanation: the “gods” are aliens. But whereas The Dæmons went into detail about how Azal’s size-changes caused the heat barrier or freezing winds, here everything is hand waved. These mummies might not be animated corpses, but Marcus Scarman is. The most science fiction idea is that events in the past can change Sarah Jane’s present of 1980, but even this is there to emphasise the horror of Sutekh’s power.

That the episode can take time out for trips to the future, and an extended sequence of the poacher Clements (who only appears in Part Two) being pursued and killed by the mummies reflects the fact that there isn’t a huge amount of plot to develop. Instead, time is spent emphasising the existential threat posed by Sutekh, and developing the charmingly naïve character of Laurence Scarman, one of a vanishingly small number of non-regulars who’ve been allowed inside the TARDIS.

Next episode: Pyramids of Mars – Part Three