Every Sunday, we pick a new episode of the week. It could be good. It could be bad. It will always be interesting. You can read the archives here. The episode of the week for the last two weeks of 2016, December 18 through 31, 2016, is “The Return of Doctor Mysterio” the 2016 Christmas special of BBC America’s Doctor Who.

Whom are we supposed to sympathize with on Doctor Who? Which character is meant to have our allegiance?

This is a bit of a trick question, because the answer changes from episode to episode. Some weeks, the show’s most poignant character is the latest iteration of the time-traveling, ancient Doctor; other weeks, he’s portrayed as borderline monstrous and the show focuses more on the human beings he comes into contact with. So there’s no one right or wrong answer.

But if I were to highlight the difference between the tenures of Russell T. Davies (who oversaw Doctor Who from 2005 to 2009 and was responsible for the Christopher Eccleston and David Tennant eras) and Steven Moffat (who’s run Doctor Who since 2010 and is responsible for the Matt Smith and Peter Capaldi eras), it would be that Davies was primarily interested in the humans around the Doctor, while Moffat is most interested in the Doctor himself. Not always, but as a general rule.

And if nothing else, “The Return of Doctor Mysterio” offers a glimpse into why Moffat sometimes struggles with the more recognizably human sides of Doctor Who, why he’s so much more comfortable writing elaborate puzzle boxes — and, ultimately, why it will be nice to see someone else take the show’s reins once Moffat leaves at the end of the upcoming 10th season.

“Mysterio” balances a very human story and a very Doctor story, to mixed results

Moffat is one of the most technically skilled television writers working today. He’s adept at structuring stories so that obvious solutions to bit problems might be sitting in plain sight, and he’ll distract you just long enough to make them feel dazzling. At his best, he’s a magician.

And the good Moffat has been on display more often than not since Capaldi stepped into Doctor Who’s title role in 2014, during the show’s eighth season. Its ninth season, in particular, felt a bit like a second wind for the series, as Moffat turned most of its stories into two-parters, allowing more room for the kind of brainteaser tales he enjoys. One episode late in season nine trapped the Doctor in a castle with a fairy-tale monster and proved to be a highlight of the whole series.

Related Doctor Who Season 9 made the show good again

The idea of a fairy-tale monster exemplifies one of Moffat’s favorite things, which is pushing Doctor Who as far away as he can from its roots as a slightly scary sci-fi program that began its life as an educational kids’ show. He loves to transport Doctor Who show into other genres. Sometimes, the justification is stronger than others. In that latter category, meet “Doctor Mysterio.”

“The Return of Doctor Mysterio” is a half-hearted attempt to blend Doctor Who with a superhero tale.

Justin Chatwin of War of the Worlds (which feels like it’s just waiting for a “here’s what the Doctor was up to when the Martians invaded” spinoff) and Shameless fame plays Grant, a young New Yorker. In a short prologue, we see him as a child who meets the Doctor, then swallows a strange alien gem the Doctor bears. (As my editor can attest, if I tried to explain to you why he swallows the gem, you would neither understand nor believe me.)

The gem grants your deepest desire, and like so many young kids, Grant wanted desperately to be a superhero. So he gains superpowers as a child, then grows up to be a masked hero known as The Ghost. Would you believe he has a crush on a hard-charging reporter named Lucy (Charity Wakefield)? Or that she employs him as a nanny, and she’s oblivious that the guy caring for her daughter is also the superhero buzzing the city skies?

In and of itself, this superhero setup could have made for a fun installment of Doctor Who, especially as the hour teases the idea that the Doctor told Grant he is not supposed to use his powers, because Earth is not the sort of place where superhero hijinks are meant to play out.

But “Mysterio” falters because it combines the superhero stuff — and its very human core of longing to tell the person you love the whole truth about yourself but fearing what might happen if you do — with a half-conceived story of villainous alien brains possessing world leaders.

The episode takes a couple stabs at “the whole world’s gone mad!” political commentary, but Moffat’s heart clearly isn’t in it. However, he also doesn’t seem entirely comfortable with Grant and Lucy’s story. So the episode gets stuck somewhere in the middle, in a muddle.

“Mysterio” is a classic example of what a showrunner does right before he’s about to leave

“Mysterio’s” misguided attempts at political commentary reveal Moffat’s Achilles’ heel — he doesn’t seem that interested in life on the ground, compared to life amid the stars. Where Davies’ Doctor Who could be slyly political and deeply personal when it came to the Doctor’s human companions, Moffat’s Doctor Who is far more taken with untangling cosmic fiddle faddle.

And that doesn’t have to be a bad thing. Moffat clearly sees a kindred spirit in the Doctor, someone who’s too clever by half but struggles to build lasting connections because of how often he outsmarts himself. (Does that sound at all similar to the protagonist of Sherlock, Moffat’s other big TV series of the moment? I’m sure it’s a coincidence.) When he sticks to the story of some sci-fi immovable object meeting the unstoppable force of the Doctor, the show is still tremendously potent.

But it’s telling that the one time Moffat’s Doctor Who has seemed to boast a truly human component in the Capaldi era came during in a handful of season nine episodes featuring Maisie Williams as a young Viking girl who was accidentally granted the “gift” of immortality when the Doctor saved her life.

Moffat posited — rightly, I imagine — that human existence would take on the feeling of a dreadful curse if you didn’t know death was coming at some point. But he also suggested that Williams’s character understood not just who the Doctor was, but that he had to be kept, on some level, from interfering too much with the affairs of humanity. He might mean well, but he screws up too often. There was an interesting tension there, between Moffat’s obvious love of the Doctor and whatever darker side he possesses.

Little of that tension exists in “Mysterio,” even though Grant could conceivably blame the Doctor for all manner of problems in his life. The episode seems to exist solely so Moffat can tell a superhero story, since he hasn’t gotten to write a superhero story just yet. (Showrunners often turn their final seasons into an excuse to try all sorts of things they’ve been half-curious about but haven’t gotten around to.) But neither Grant nor Lucy rises to the level of character, instead of caricature. Instead, as always, the figure we’re most meant to sympathize with is the Doctor.

How many times can we watch the same man give the same speech to yet another race of aliens bent on conquering Earth? How many times can we watch him feel bad about his lack of interpersonal connection? How many times can he prove he’s the cleverest, bestest hero of them all? Moffat’s time on Doctor Who has been more good than bad, but I’m more than ready for a shake-up.

Doctor Who airs on BBC America. Season 10 will launch in 2017.