With “Thin Ice,” writer Sarah Dollard follows up last season’s “Face the Raven” with another successful episode whose central focus is the relationship between the Doctor (Peter Capaldi) and his companion—in this case, Bill (Pearl Mackie). As we saw at the end of last week’s episode, they’ve arrived at the end of the last London frost fair in 1814. This event had been mentioned in passing in 2011’s “A Good Man Goes to War,” where River Song said the Doctor had taken her there as a birthday present. There’s no hint of any timestream-crossing plotting here though: This episode sticks to the more straightforward storytelling style that’s characterized this season so far.
Part of the fun of “Thin Ice” is how Dollard takes the historical fact that this was the last time the Thames froze over, after doing so regularly once every decade or two for centuries, and provides a suitably Doctor Who-ish explanation involving a giant monster living in the river. The production design is ambitious, with the huge expanse of frozen river, populated with fairgoers, stallholders, acrobats, and even an elephant at one point, providing a strikingly unusual arena for the adventure. Equally impressive is the sequence as the Doctor and Bill use some borrowed diving equipment to investigate mysterious lights under the ice and discover the enormous, eel-like creature chained to the bottom of the river. Both of them are also resplendent in Regency-era costumes, and Dollard takes the opportunity to incorporate a homage to the modern series’s first historical episode, 2005’s “The Unquiet Dead,” as the newly dressed-up Bill enjoys leaving her first footprint in the snows of history, just as Rose did 12 years ago.
Like the companions before her, Bill is full of questions about the dangers of traveling back in time, echoing the concerns raised by Martha in 2007’s “The Shakespeare Code” about accidentally changing the future, and whether she needs to be especially wary due to the color of her skin. But their bantering over these theoretical worries is cut short when they encounter a gang of child pickpockets, one of whom snatches the Doctor’s sonic screwdriver before the swirling lights (created by bioluminescent fish that catch prey for the huge beast) trap him and pull him under. The Doctor manages to recover his screwdriver but is unable to save the boy.
Shocked by the death and the Doctor’s seemingly muted reaction to it, Bill questions him about how many people he’s seen die—and how many he’s killed. Apart from its literal meaning, the episode’s title could also refer to the way Bill slowly edges her way into an understanding of the moral complexities of time travel the Doctor is constantly contending with—as happened with Donna in 2008’s “The Fires of Pompeii.” Rather than overwhelm her with the terrible events of his past, he stresses that his response is always to move on: “I’m two thousand years old, and I’ve never had the time for the luxury of outrage.” Though still disturbed by his words, Bill in her turn begins to “move on” as she talks to Kitty (Asiatu Koroma), the gang’s leader, making promises that the Doctor will help them. At one point, she’s even able to laugh at the Doctor’s attempts to be “down with the kids” (“My hair was cringing”).
As with the previous two episodes, Capaldi and Mackie bounce off each other brilliantly as they navigate the shifting relationship between Bill and her mentor. Their interactions are far more interesting than the villain of the piece, Lord Sutcliffe (Nicholas Burns), an industrialist who’s somehow using the waste produced by the beast to manufacture incredibly powerful fuel for his steel mills, and who plans to bring the fair to an end by using explosives to break up the ice, thereby feeding hundreds of victims to the creature. Sutcliffe is a one-dimensional caricature who would certainly be twirling his mustache if he had one, and one of his very first lines is a crude racial slur directed at Bill in order to make it clear that he’s completely irredeemable.
The Doctor, though unable to resist administering a punch on the jaw, eventually responds to Sutcliffe in more characteristic fashion with a declaration which, while it doesn’t have the rhetorical fireworks of the anti-war speech in last season’s “The Zygon Inversion,” is just as passionately delivered by Capaldi: “Human progress isn’t measured by industry. It’s measured by the value you place on a life—an unimportant life, a life without privilege. The boy who died on the river—that boy’s value is your value. That’s what defines an age, that’s what defines a species.” Though it fails to move Sutcliffe, Bill is greatly impressed, and the contention between her and the Doctor is healed as she teases him over his earlier denial of being outraged.
The Doctor now wants Bill—as a representative of the future of the human race—to decide whether he should free the creature. It’s a much more believable version of the ethical conundrum posed in 2014’s “Kill the Moon,” with the Doctor being reluctant, as an outsider, to make this sort of decision. Showing that she’s now ready to be a fully fledged companion, Bill gives him the go-ahead, and while she and Kitty’s gang warn the fairgoers to get off the ice, the Doctor secretly redeploys the explosives so that, when Sutcliffe sets them off, they shatter the creature’s chains. The episode reaches a storybook conclusion as the villain receives his comeuppance by drowning, the freed creature leaves London for colder climes, and the eldest boy of the gang, thanks to some help from the Doctor, “inherits” the Sutcliffe fortune.
When the Doctor and Bill return to his office in the present day, there’s an amusing confrontation with Nardole (Matt Lucas) that brings the season arc plot about the Doctor’s mysterious vault back to the foreground. After the Doctor faces him down, the disgruntled Nardole returns to the vault, from which comes an ominous knocking. He’s clearly worried but tells whatever it is that, even though the Doctor might be distracted by his new friend, “You are going nowhere!” What is it that’s trying to get out? Stay tuned…
Next Week: Bill experiences a haunting adventure in her own home, in “Knock Knock.”
Classic Doctor Who Recommendation: Surprisingly, “Thin Ice” isn’t the first time the Doctor has encountered a gargantuan aquatic beast whose waste products are being extracted by human exploiters for their own profit. The previous occurrence can be seen in 1978’s “The Power of Kroll,” starring Tom Baker and Mary Tamm.
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