This one feels like a late 1970 British horror movie (I’m thinking something like Killer’s Moon), with a tiny cast lost in vast, remote countryside, and with zero budget. The eerie emptiness of Dartmoor works in its favour, although it’s a shame this isn’t on film as there are a couple of moments when director Rodney Bennett focuses on little details, like water dripping down the rocks, that emphasise the loneliness of the location in the same way Lawrence Gordon Clark often did in his filmed M.R. James adaptations. Nevertheless, I think the sweeping shots of the moors and vast skies are the most interesting thing about this, particularly as it makes an interesting contrast with the previous studio-bound episodes.

I also like that we see the flipside of the Ark’s sterile elite. The GalSec astronauts, who speak with South African accents to emphasise their colonial background, are proud that they kept going, and made a new empire for themselves without the help of the ‘Old People’. The Ark’s inhabitants, who in the last serial seemed to be the last best hope for Earth, are here dismissed as a ‘bunch of survival sleepers’, as if they’re actually survivalist cranks who buy into ‘that Mother Earth rubbish’. And given the sleepers’ own attitude towards colonists, suddenly the future of humanity seems a lot less rosy than it did at the end of the last episode.

It doesn’t help that we know we won’t see any of this come to pass. In context, this does feel like The Ark in Space – Part Five; the contemporary audience would mostly have had no idea this was going to be a two-part interlude and might reasonably expect that we would see colonists and sleepers coming into direct conflict. Now, we know it’s just adding some flavour and continuity to a story that’s actually about getting their money’s worth from the expensive Sontaran costume and props. Holding back the reveal to the end of the episode, and replaying the memorable cliffhanger to The Time Warrior (albeit the redesigned Sontaran mask looks less impressive) means that this is a lot of set up for very little pay off.

But it’s entertaining for a week, which I suppose is the main point. Tom Baker, making his fifth episode (this was recorded before The Ark in Space) is still refining his performance, and plays this more flippantly. His sniff and lick soil test is a touch Tennant appropriates, and the ‘I just love clocks’ sequence is indicative of the comic facetiousness to come. Styre’s robot used to come in for a lot of criticism but the joke’s on us as it looks like every explorer we’ve sent to Mars this century.

Next episode: The Sontaran Experiment – Part Two