In “Thin Ice,” the Doctor and Bill visit the last ever Thames Frost Fair and uncover a mystery, as the Doctor and his companions are always wont to do. It’s highly reminiscent of other Regency-to-Victorian era episodes of the show as well as of the season five adventure, “The Beast Below.” If this season of the show has an overarching theme so far, it seems to be rehashing all the show’s old tropes in new arrangements, and this is both fascinating and frustrating. To be fair, there’s precious little new under the sun, and I don’t expect to be blown away by the originality of the show week after week, but I’m not certain that this most recent iteration of the series is doing enough to set itself apart from previous seasons. There’s some great stuff in “Thin Ice,” but there’s also some tiresomely dull stuff, a tendency to zoom past emotional moments without giving them time to really land, and a sense of self-righteous smugness about some of the episode’s messaging.

Once again, Bill is proving herself to be a great companion to the Doctor, and we’re starting to see more and more of the easy chemistry and nicely accomplished comedic timing between Pearl Mackie and Peter Capaldi. Bill’s a little bit street wise, and she’s got a sensible level of independence along with a stubborn streak that lets her stand up to the Doctor, who can be a little bit of an intellectual bully at times. Bill’s confidence and cleverness let her adapt to unexpected situations, and the joy she takes in novel experiences is infectious and quite fun to watch. At the same time, this season is continuing very deliberately the themes of the last two seasons relating to the Doctor’s lack of humanity, and like previous companions, Bill is becoming something of a conscience for her mentor. Unlike with the last couple of companions, however, the show is doing a great job of truly showing us why and how Bill is up to that often onerous task.

**Spoilers below.**

This week’s mystery revolves around a great beast chained to the bottom of the Thames, where an unscrupulous nobleman, one Lord Sutcliffe, is feeding it humans in order to extract a valuable and highly efficient fuel that the beast produces as waste. It’s a simple enough plot and a straightforward mystery without any unexpected twists or turns, but that’s fine. There’s something to be said for that kind of comfort television, and “Thin Ice” is definitely in the comfort TV neighborhood. It’s got lighthearted fun, cute kids, and a happy ending where a racist asshole gets what’s coming to him. There’s not much not to like about it. Unfortunately, there’s not much in particular to actively praise about the episode, either.

Perhaps the episode’s biggest problem, though it’s by no means a dealbreaker, is the ease with which it skips from emotional beat to emotional beat without taking time to really examine why these moments are supposed to work. Bill’s concerns about facing racism in Regency England are quickly moved past, as are her concerns about her potential to change the future in unexpected ways. In a show that in general takes a blithe attitude towards its treatment of most of the usual ethical and practical considerations surrounding time travel, it may be best to just leave it alone. I did rather like the Doctor messing with Bill about it, but even that isn’t terribly funny if you think about it; he’s joked around Bill’s concerns rather than actually answering them.

When a little boy dies right in front of Bill’s eyes, she’s outraged at the Doctor’s lack of reaction—and it’s not touched on, but he saves his sonic screwdriver without making a move to save the child—but even this is quickly glossed over. At first Bill seems deeply upset by the experience, and she’s angry with the Doctor for being able to move past it so quickly, but she moves past it fast enough herself. It’s an interesting way that the Doctor seems to corrupt his companions. By removing them so far in space and time from their natural contexts, the companions are often forced to abandon normal human standards of ethics and morality in favor of more broadly logical, but surely less humane, rules for living. For all that the show continues to try and portray the companions as a humanizing force in the Doctor’s life—and the Doctor gives Bill a great deal of power and agency in their partnership this week by treating her as a sort of commander—the ways in which the 2000-year-old Doctor changes his companions tend to never be adequately dealt with, and this episode is no different.

As far as the overall messaging of this episode, it’s a decidedly mixed bag. It’s nice to see fictional whitewashing called out, and I’m always happy to see a racist get punched in the face, but did the Doctor really need to give a long-winded speech about the sanctity of life or whatever? The decision to free the Thames sea serpent thing at the end of the episode is laudable, but it’s done with an awfully self-satisfied tone considering that there’s no assurance that the beast isn’t going to leave to be a human-eating menace elsewhere. As fantastical as the episode was, we also get a reminder that a black girl couldn’t inherit a fortune in 1814, which necessitates it being given to a little white boy with a much smaller role in the episode. It’s fine, I guess. Whatever. But the overall tone of the episode verges on smugness, especially in the delivery of the Doctor’s lines about whitewashing and his speech about what the true measure of humanity’s goodness is.

For all that the folks behind the show do seem to be making an effort to engage with and address common criticisms, they’ve still got a regrettable tendency to always want to prove that the Doctor is the smartest and best person in the room. He might need a human companion to keep him in check and remind him to do the human thing, but that’s not going to stop the Doctor from making self-indulgent pedantic speeches that challenge the humans around him to be better than they are. Yay.

Miscellaneous Thoughts:

• The episode seems to imply that Frost Fairs were common occurrences on the Thames, but they weren’t. Even during a mini Ice Age that caused more extreme than usual winters in England, the Thames never froze solid enough for this kind of thing more than once every ten years or so.
• I guess Nardole is part of the overarching plot this season but not adventuring with the Doctor and Bill. Too bad, though. I would like to see Matt Lucas get a bit more to do.