There’s something very Star Trek about a culture built entirely around the remains of a survey expedition from Earth, with sacred artefacts, rituals and names drawn from corrupted memories. ‘Are we their captors or their children?’ Calib asks shrewdly. And the idea of the Doctor’s past coming back to haunt him feels quite in keeping with the theme of the previous story: the moment when he has to talk to himself (or at least, Xoanon speaking with his voice), and his nagging unease about what he might have once done is great. It’s a shame Boucher left the show after Season 15, as I feel his approach would have absolutely synced with Christopher Bidmead’s: credible SF but with a good dose of horror too.

I’m enjoying Tom’s performance: he’s still largely playing it straight. His desperate race to find the antidote for the poisoned Leela is very tense, and he retains a dangerous edge, such as when he threatens Calib with a crossbow, or kicks a horda onto a Sevateem man who slaps Leela (shades of the 12th Doctor punching a racist there). But he’s injecting more humour as well: ‘I like the hat, very fetching’ and his faux outraged, ‘No it isn’t up the nose!’ I’m also looking out for his chemistry with Louise Jameson: by all accounts this was a fairly spiky relationship, and it’s interesting – after Tom and Lis were such a great double act – to see how relatively little eye contact he makes with Jameson.

This is quite good so far, although I’m not sure the attack on the time barrier made a huge amount of sense. The cliffhanger is also very weak: not the Doctor and Leela being menaced by something inside his statue’s mouth (not the last time Leela will venture inside the Doctor’s head), nor a ghostly doppelganger of the Doctor attacking Tomas and Andor. Instead, it’s Tomas looking a bit scared and firing his gun.

Next episode: The Face of Evil – Part Three