A fun episode and aside from The Doctor talking to Ashildr and Clara, there’s much silliness.
Again, The Doctor raises his ‘duty of care’ over Clara and in a further conversation toward the the end expresses his frustration at being sick of losing people.
There’s a heart felt chat with Ashildr, on the puppets and home. A question is whether the doctor did recognise her or whether his deja vu in reverse was just a thing
The story is resolved through trickery to overcome ‘The Mire’, after hope is all but lost. The Doctor winning in the way the Doctor does and throwing a curve ball at an enemy using technology to be gods.
An emphasis on ‘The Story’ created by The Mire and their reputation and how their fear is created.
Maybe fear of a story over fear of the reality, a tale of perception.
But Ashildr dies through using the connections in The Mire helmet.
In the grief of her loss, The Doctor rails at the thought that he can do anything but is constrained by ‘the rules’, he then has a moment of clarity and realises why he has his face. It’s a reminder that he can save people, that he is The Doctor.
The Tennant and Donna flashback was enough, not over long, not over pushed.
In saving Ashildr he makes her effectively immortal, a Hybrid. The Doctor then talks of immortality and loss. There’s a montage of Masie Williams that uses music and visuals splendidly but the change from hope to despair to a final look that could be ominous and The Doctor has realised just that when he returns to the TARDIS.
There’s tidals waves and ripples according to The Doctor when Clara asks him what are ‘the rules’ at the beginning of the episode.
I’d suggest the significance of this episode is at the very beginning and at the end. The speeches about the rules and what The Doctor supposes he can and cannot do, his realisation on why he chose the face of the Roman Merchant and his ‘I’m the Doctor and I save people’ exclamation. There’s significance to his chat with Clara both before he has a plan and after realising the helmet has killed Ashildr. He worried about Clara again suggesting ‘A Hobby’ for Clara to reply ‘You’re my hobby’.
That exchange shows where Clara has gone, she’s not just a human interface with The Doctor, she’s now significant in her own right as a time traveller. Until Ashildr challenged the leader of the Mire, Clara had near enough called him out as a fraud for farming warriors, she had spoken words in a way A Time Lord might have used to challenge the morality and lies behind what the Mire do and very nearly got him to leave the village in peace. Brave or Stupid? Maybe The Doctor is right to be concerned.
We have a building of the arc. Consequences of time travel, the Beethoven opening monologue, actions being noticeable on Earth in his ‘meditation’ to the paradox of the ghosts in the Drum from the Fisher King. The reference to the Time Lords once being curators to The Doctor yelling ‘who can stop me?’
We’re not quite at ‘Time Lord Victorious’ and ‘I’ve gone too far’ after the events of Waters of Mars, but a slight difference in The Doctor thinking as Ten that he was the last Time Lord left to Twelve as an ‘Idiot in a Box’ realising that he can save people and that’s what he wants to do, despite ‘the rules’.
I suspect we will learn more about the rules and there’s more consequences to come from The Doctor meeting Ashildr again.
So, overall, A romp of an episode and the further seeing of where the season is headed. An excellent enjoyable episode.