‘This is the graveyard of all those taken from Earth.’ I really like the macabre turn this episode takes: not only that the crew are android copies of humans abducted thousands of years ago, but the fate of their flesh (Enlightenment talks about being ‘relieved of the flesh time’ with a shudder) after the android duplicates are created: ‘The subject is then terminated and their body used to fertilise the Flora Chamber.’ This is all explained by Bigon, through neat scene shifts back and forth, as Nyssa is prepared to undergo the process. It gives a pungent oomph to this that was lacking in the frothy first half.

I also like the revelation that Monarch is a properly insane megalomaniac, whose plan involves learning the secret of faster than light travel so he can travel backwards in time and meet himself, as god, at the dawn of creation. It has a lunatic grandeur to it that’s very Season 17. And, modishly, Monarch is the destroyer of worlds: his technology has destroyed Urbanka’s ozone layer and laid waste the planet hence the Urbankans’ need for Earth.

The downsides are some, presumably, Ian Levine continuity additions (‘There is a galactic legend about a Rassilon. He who found the Eye of Harmony’). And Terence Dudley’s inability to find enough material to occupy four regulars: not unique to him, but very obvious from the way Nyssa is silenced, then has to stand about like an afterthought as Lin Futu’s men prepare to execute the Doctor. Adric gets taken in by Monarch’s professed desire to save humankind from itself – which means an argument with Tegan, fresh off the back of her argument with the Doctor. Both Tegan and Adric are unreliable – Tegan defies the Doctor, and rushes off to steal the TARDIS. Adric betrays him. Nyssa does, again, get to mention her father’s fate (‘I can never forget that my father was killed by a tyrant’) – making it more of an ongoing concern than I remembered.

In the middle of all of this, Davison’s Doctor, now he’s found an ally in Bigon, is full of energy and ideas. Again, several of the scenes in this were taped early in recording (a lot of them on Davison’s second day), and he hasn’t quite found his groove – not helped by more very old-fashioned exclamations (‘The devils!’, ‘Oh good grief!) but seeing him dash about it’s hard not to get swept up in the excitement.

Next episode: Four to Doomsday – Part Four