Doctor Who and Arya Stark are an amazing combo

This week on Doctor Who: Vikings, fake gods, a terrible decision by the Doctor and finally the answer to why the Time Lord chose this face for this regeneration. If all of that sounds like a lot to pack in and thus a reason to panic; don't. This is actually a really good episode, which felt like a science fiction version of ¡Three Amigos!, but with just enough twists in the formula to keep things fresh.

In contrast to last weeks disappointing conclusion to "Under the Lake," this story managed to start things off in the right way with Clara floating alone in deep-space, while a hungry alien spider crawled up the inside of her space suit to feed on her brain. Here we were at the end of one of their many fast-paced adventures, with the Doctor managing to save his school-teacher sidekick just in time with an impressive materialization. It's this sort of electric atmosphere we enjoy seeing with Doctor Who, but the action soon grinds to a halt when the TARDIS lands on Earth and the duo are captured by Vikings. Of course the Doctor scowls at the very idea of this as he appears to dislike Vikings for some reason, threatening them with the use of his advanced sonic sunglasses technology.

Unimpressed by this, the Vikings snap them in two. RIP, sunglasses.

There's no getting out of this scenario easily for the TARDIS crew, and just like that another adventure begins.

GODS VS VIKINGS

After two days on a longboat in shackles, the Doctor and Clara meet the villagers of a Viking village, a nice change of setting for the episode compared to the dreary underwater bases and planets of recent stories. With no gloomy corridors to run down, or quarries in which to walk aimlessly, it felt like the episode would be a lighter adventure for the duo. Obviously that's not entirely the case here. It's after a brief stint of pretending to be the Norse God, Odin, that the assembled crowd actually come face to cloud with what seems to be the real deal.

Of course, it's not the real Odin speaking from the heavens but obviously the locals don't believe the Doctor when he tells them that. When the bravest warriors of the village are "summoned to Valhalla" to feast with Odin himself there's very little he can do but stand by and watch. That doesn't stop Clara from asking local girl Ashildr, portrayed by Maisie Williams of "Game of Thrones", to unlock her shackles using part of the broken sonic sunglasses, which in turn gets the attention of the raiding party who transport the women away along with the men.

With no blue box or sonic technology at his disposal, the Doctor had no way to help the abducted, leaving the fate of those on Odin's ship to Clara. This is a really cool situation because it gives Clara a chance to once again flex her "Doctor muscles," first seen in last years episode "Flatline" where she faced down the Boneless after the Doctor was trapped inside a shrinking TARDIS.

After the warriors on board the ship were transformed into a liquid, which fake "Odin" then imbibes in front of the shocked Ashildr, we see Clara switch to her "Doctor" persona. In fact, if you notice how she greets the soldier who passes her holding the vial, many of her visual mannerisms and audible cues are similar to those of the 11th Doctor. It's lovely, it's endearing and it makes for a reminder of what we loved about that incarnation of the character. Unfortunately it also shows how much loss has changed her over the last two years, where she's become numb and indifferent to the loss of life in order to aid the larger victory.

When we were introduced to the 12th Doctor we had this hint that he was a darker, brooding character who needed the warmth and kindness of his friendship with Clara to rediscover whether he was a good man. Now it seems that they're passing like ships in the night, with the humanity of Clara Oswald slipping away week-by-week as the harsh exterior of the Doctor continues to soften.

Maisie Williams is a fine addition to the Doctor Who universe as Ashildr. Many will know her as Arya Stark in HBO's Game of Thrones, and you'd be hard pressed to visually identify any differences between the two characters upon her introduction this week. That being said, the scene where Ashildr declares war on the village's enemies is a powerful moment that undercuts Clara's Time Lady-like confidence, and sets up a difficult challenge for the Time Lord to solve.

How do Viking villagers ever hope to defeat an invading force from space?

HOW TO TRAIN YOUR VIKINGS

Meet Chuckles, Daphne, Heidi, Limpy, Lofty, Noggin and ZZ Top. The last, best hope for saving this village from space monsters. This might be silly for some, but I enjoyed the nicknames of these not-warriors, as well as the interplay between the different characters up until the accidental burning of the village longhouse. It's the kind of comedy that feels right for this story, and for the younger audience that the show is really meant to be for. Even though the villagers stand no chance against the militaristic forces of the Mire, you just have to admire their moxie.

After all, we're told a Viking death is a good death.

Equally as silly, but also quite powerful were the scenes in which the Doctor speaks "baby" to Lofty's child, showing Peter Capaldi once again adding depth in scenes that the characterisations of his predecessors would have struggled. These translations of a crying child turn out to be some of the more emotive beats in this story, if not any story of this Doctor's tenure thus far. When he translates the line "Beyond the folding of your smile, is there other kindness?" it's very sorrowful, and weighted in its delivery. It's a skill the 11th Doctor brought out a handful of times, but while those instances were off-the-cuff and comedic the 12th Doctor feels the burden of every word here.

It's from the mouths of babes that the Doctor has the beginnings of a plan to defeat their foe.

"Fire in the water." Or rather, let's electrocute the invading army with the electric eels in our boathouse. Clever thinking there, baby human.

"Beyond the folding of your smile, is there other kindness?"

The resulting battle between the Mire and the Vikings was one that was pretty well planned and executed by the Doctor. In order to defeat a vastly superior force they had to resort to cunning, much like the Three Amigos had to when faced with the forces of El Guapo. Where the villagers of Santo Poco were able to fabricate professional grade weapons, costumes and outsmart their invaders, the reality of the Who universe called for something more down to Earth.

I know, we're talking about a universe where a box is bigger on the inside so the concept of "reality" is kind of subjective, but using the aforementioned eels to gain access to one of the helmets of the Mire was a stroke of genius. Knowing that their leader Odin was using a hologram to disguise his appearance, Ashildr would use that against the Mire by providing one of her own in the form of an attacking serpent.

It worked, but ultimately at the cost of her life, which left the Doctor angry and emotional. Did you see how he walked, then ran from this scene? He sold the weight of the moment here, allowing it to carry through to the end of this particular story and into the next.

THE TIME LORD VICTORIOUS, AGAIN

This felt wrong for me. This moment was something we'd waited for since we knew Capaldi would be the 12th Doctor, but the reveal came from such a seemingly unimportant moment. Having previously appeared as Caecilius in the Series 4 episode "The Fires of Pompeii," we were promised that there would be a reason for his choosing of that face. It turns out that it was a reminder that he could always choose to save a life, even if it meant more than just a potential ripple in the fabric of time. There wasn't any obvious fallout from saving the family of Caecilius, and maybe that's what guided his decision here. The Time Lord Victorious, from a brief period where he got things so very wrong, had returned.

Almost instantly we're shown why it's a bad idea for the surveyors of all time and space to disregard the rules out of selfish desire. In choosing to save Ashildr, the Doctor does exactly what he had previously accused the Fisher King of in the previous episode, "Before the Flood". To save this girl he violated the laws of life, and in turn robbed the Viking girl of the ability to die -- resulting in a kind of immortality similar to that which Captain Jack Harkness and Torchwood's Owen Harper possessed. His realization of what this could mean comes days after he and Clara return to the TARDIS, that a small part of Ashildr is now alien and she may just be the hybrid of which an old Gallifreyan prophecy speaks.

It's definitely not what I was expecting the hybrid to be, and maybe it's a red herring of sorts to distract us from the ever approaching series finale but I'd like to think that this is just another time where the Doctor thinks he has it all figured out, but is completely, utterly wrong.

NEXT TIME

• The Doctor and Ashildr meet once again, this time in the 1600s. No longer a girl, but not quite a woman, Ashildr is somewhat like the character of Claudia from 1994's "Interview with the Vampire" here. Never ageing, but never quite maturing either.
• This time the Doctor needs her help, and can't run off like he apparently always does. Have the two met at some point either before or since the last episode?
• Will we see the consequences for breaking the laws of life?

That's another recap down folks. How did you get on with this week's episode? Remember that you can follow along with this series of Doctor Who via our StoryStream, and if you like that why not check out the rest of our television coverage here at Polygon at the following link.