Okay, quick recap. The Doctor is tasked with repairing a malfunctioning "good" Dalek. Him, Clara, and three soldiers from some future time are miniaturised and head off for adventures inside the psychotic pepper pot. The malfunction is repaired, "Rusty" turns evil and goes on a killing spree. The rest of its brethren turn up and more people die until Clara reverses the polarity and makes the Dalek see beauty. After
This episode is a meditation on war or, rather, soldiery. As everyone knows, the Doctor is a big old liberal middle class lefty. He's the sort who'd put Benecol on his morning muesli to keep his two hearts healthy. He abhors violence, hate suffering, is opposed to war and, as such, is suspicious of soldiers. If this couldn't be underlined enough, when asked by Lt Journey Blue to take her with him he rules it out simply because she's military. This I think is the leaping off point for a veiled polemic we can look forward to over the course of the series. The Doctor encapsulates the liberal pacifism of a layer of people for whom soldiers are something to be reviled, as automatons trained to kill in exchange for a modest wage and perhaps the skills for a trade, as per army recruitment ads. Bag a terrorist, learn carpentry. I expect by the end of this season his attitude will have grudgingly changed and maybe Lt Blue will come back either as a recurring character or future companion.
Idle speculation? Yes, it is. But not without further supporting evidence signposting this destination. Like last week, we're running parallel story lines. The Dalek is your wehrmacht and einsatzgruppen rolled into one. Unlike real life they are crack troops and death squad, utterly pitiless yet incomparably formidable. The Doctor knows what he's dealing with: he wiped them out, once. And yet he is intrigued by the possibility that this one might have broken with Dalek essentialism. He speculates the malfunctioning of its life support system may have altered its consciousness. Eventually his team locate the source of the problem: a radiation leak. He seals it up and, quelle surprise, it returns to type and everything goes to hell. Even then as it starts killing the Doctor still gives the Dalek his time. He knows the good memories are still there, albeit repressed. They just have to be liberated and perhaps it can be turned back. This is done successfully as the Doctor and Dalek share minds. It learns beauty from the Doctor once again, it relearns that the destruction its race visits upon the universe is pointless because the cycle of life and rebirth never ends. But it also sees the Doctor's own hatred of and reverses inflicted on the Daleks. His hate joins with the Dalek's hate, his disgust powers the Dalek's emerging rage against its own people. In trying to change the Dalek, all the Doctor has managed to provide is a new enemy for it to fight against. It's still a soldier, still a creature who lives by and revels in violence. It cannot be changed. All military personnel are permanently damaged and scarred by death.
And then there is Danny Pink. He's the yummers new maths teacher at Clara's school, but with a lot of baggage on his back. Socially inept and shy, he initially refuses her offer of a drink after a trying day in the classroom. You see, it turns out he's ex-military. His inner turmoil not-so-subtly hinted at by the appearance of a solitary tear when asked if he'd killed any civilians. You can see how this is being set up. After the Doctor's experience with the Dalek, his belief in the rigidity of the martial character has been reinforced. And yet coming along is a potential love-interest for Clara destined to challenge the doctor's prejudices. Here's a man who's broken with his army programming and wants to atone by helping kids achieve. It's sadness and guilt that drives him, not bloodlust. One assumes that as the full complexity of his character is brought out, the Doctor will learn that military-types are just as changeable as anyone else, that they are more than the sum of their grim experiences and actions. And to drive the point home? Clara and Doctor stomping around prattling about "the lesson learned today", and much more emphasis on her character as a teacher than before. Soldiers are more than Dalek killing machines, and the desired learning outcome for the rest of the series is getting him - and you - to appreciate this.
Why take this line of flight? Who knows. Maybe Moffat is hitting back at the liberal, feminist lefty types always pulling him up on dodgy gender politics. Perhaps he wants to reposition the Doctor as someone who's dealt with his own war demons and more sanguine about violence. After all, there were several occasions SmithDoc went unperturbed by deaths he caused/contributed toward. Taking pacifism and rubbishing it might be up his street. There's one in your eye, lefties!