There’s a monster living under the Thames, and it’s eating people.

An ice covered river, street urchins, and the Doctor in a top hat – this episode has it all.

A definite improvement on last week, resolution-wise, but somewhat lacking in a grand climax. There are some wonderful moments, and once again the spark between the Doctor and Bill is the star of the show.

“Slavery is still a thing”

The episode opens with Bill addressing something that people have been talking about especially since The Shakespeare Code. The fact that the history of Britain is less than kind to non-white people. The Doctor takes a moment to acknowledge the horrors of slavery, a haunted look passing over his face, before moving on. It wasn’t much, but somewhat better than the 10th Doctors ‘Just walk like you own the place’ attitude.

A little later, Bill comments on the fact that Regency England is a lot more black than they show in the films. The Doctor’s “So was Jesus” response was pretty much perfect. The episode then introduces us to a group of street urchins of various skintones and despite some initial setbacks – namely the death of one of them – the Doctor and Bill soon forge a friendship with them.

When, somewhere towards the third act, the Doctor and Bill confront a racist aristocrat, it should come as no surprise that it does not end well. This is a good bit of build up and pay off from writer Sarah Dollard – having established more of a healthy relationship between the Doctor and diversity, when he is faced with a truly awful man, he reacts accordingly.

Punching racists is nothing new for the Doctor. Fans of the Third Doctor – Jon Pertwee – may remember his fondness for Venusian Akido. Though he would often seek a diplomatic solution, he wasn’t beyond dealing out the occasional chop to the neck.

In this instance, with the Doctor very much choosing to side with the marginalised against the upper crust, it is very much a case of the Doctor’s true qualities coming through. As the Seventh Doctor once said, ‘You can judge a man by the quality of his enemies’.

“How many people have you killed?”

Where this episodes – and indeed this series at large – has been impressing me the most has been in the relationship between Bill and the Doctor. The student – teacher dynamic has left something of a power imbalance, but that hasn’t stopped Bill from questioning the Doctor on his ethical choices.

The Doctor may be a goofy space wizard, but he is also dangerous. He is a deeply moral person, guided by some closely held principals, so when he goes against these principles, it takes a toll on him. This is a theme Moffat has explored before, albeit somewhat clumsily. This year, so far, we have seen a more subtle approach, a more delicate touch to the theme that works a little better.

Think back to 2005’s opening episode – Rose – where the audience’s first impressions of the Doctor are those of the dangers he poses. Explosions, historical tragedies, and death. We are show his dark side first, and then allowed to discover the goodness that lies beneath. Moffat has often taken the opposite approach, focussing firstly on the Doctor’s funnier sides before diving into the darkness beyond.

Bill has a very human reaction to seeing another person die before her eyes. This is a refreshing change from a lot of Moffat’s companions who have had a quip on their tongue as their prominent response to most things. Which is fine occasionally, but when it dominates the characters we see, it gets a little stale. Seeing Bill have such a visceral response makes her more human, and really grounds the show in reality. When a story reaches the heights of the fantastical, something to anchor it to the audience’s real lives so often keeps people invested.

You say you want a resolution

The ending of this episode was an improvement on last week’s, for sure. Thematically consistent, and just exciting enough to stay within the tone of the episode. While I had been somewhat expecting something more visually spectacular from a giant sea monster swimming though the Thames, it was okay.

You may be wondering how nobody saw this monster during the times the river wasn’t frozen over. And, yes, this is an issue that never really gets addressed. I suppose in the same way the Loch Ness Monster manages to stay hidden for so long, eh?

Perhaps a good visual metaphor was when the Doctor and Bill are hit by a splash of water from the creature as it passes. It did look a bit like somebody just tossed a bucket of water at them, rather than a giant sea monster had swum by. Budget cuts, I suppose.

The Doctor freeing a prisoner, and putting an end to a system of oppression for the sake of greed. This feels a very timely message given the current political climate and fits well within the Doctor’s character and drive. With Bill there to push him to explain himself, to teach him as well as learn from him, I have no doubt they will continue to be one of the best Doctor-Companion duos of recent times.

And finally

The series arc – what’s in the vault? What was the Doctor’s oath? All mildly interesting, I suppose. Where the threads of this are perhaps weakest is a lack of it being tied to the Doctor and Bill’s life in anything other than a tangential manner. The mentions so far feel a little tacked on, but as we are only three episodes in, that’s forgivable. It took a while for ‘Bad Wolf’ to be a thing we took notice of.

It also seems to be a mystery that cannot grow on its own, but one that needs to be prodded. This happens with any box or vault based mystery. Unlike, say, Mr Saxon or the Darkness, which grew and developed in spite of the Doctor, this relies on his personal attention to become narratively significant.

In those former arcs, the audience became aware of the peril before the Doctor did, thus giving us more of a sense of urgency and an ability to put the pieces together. Here, the Doctor holds all the cards, and hides them from the audience. This can be done to great effect, if enough clues are sprinkled, but it can also create a distance between the audience and character. If the characters and the audience discover a mystery together – or if the audience feels they are one step ahead – it can make us more invested.

Still, as I said, we are only three episodes in, so let’s give them time to flesh this out.