After a couple of weeks where she’s been relegated to feeding the Doctor lines, Vicki finally gets her mojo back, freeing the Doctor from the Animus’ power and leading their escape from the Carsenome. Along the way, she picks up Zombo the Zarbi, presumably as some kind of replacement for Sandy the Sand Beast.

Meanwhile, Vrestin and Barbara have stumbled into one of the ancient Temples of Light, ‘sewn into the craters and plateaus of Vortis, being slowly un-woven by the silence of time and their entrances long forgotten by our species.’ And just as Vicki has taken the lead in escaping the Animus, so Barbara takes the lead in persuading the Menoptra to attack the Carsenome, and planning the assault. In fact, between Vicki and Barbara, the voice of the Animus and the female Optera and Menoptra, this story has one of the strongest woman casts so far.

William Russell has looked increasingly peeved by some of the stuff thrown at him over the last few weeks, which adds an extra frisson to Ian’s grumpy response to the line, ‘A silent wall. We must make m mouths in it with our weapons. Then it speak more light.’ ‘Dig you mean,’ he replies, testily. He makes up for it though with his appalled reaction when Nemini shoves her head into an acid breach to save their party.

Other observations:

in their exchange about Prapillus’ plan, Hartnell and Hill are brilliant – she plays him through flattery, and with a fleeting expression we can see he knows it, but he also knows she’s right, and so reluctantly hands over his ring.

The line ‘Yes, what is it, what do you want?’ is cut and pasted into the first Doctor and Clara segment of The Name of the Doctor.

Next episode: The Centre