Big twisty mind-blowing arc episodes like “Let’s Kill Hitler” are fun, but this show isn’t really about its main characters. The need for a central mystery is right there in the title. This is, in fact, how the show has managed to continue for 48 years in one form or another; it’s an anthology show, given continuity through an always-changing main character and an ever-rotating cast of (admittedly not always that distinctive) supporting characters.

We’ve learned a little bit about where the Doctor comes from over the years, but still very little about the Doctor himself. That’s why the increasing sense these past two seasons that the universe revolves around the Doctor himself is so worrying. This show’s longevity depends on keeping the focus off who’s doing the travelling, but and on where they’re travelling to.

So “Night Terrors” is in some ways a step in the right direction. The Doctor, Rory, and Amy are there to explore the world of the week (in this case a high-rise tower block, which through inspired cinematography ends up looking as fresh as an alien planet), bring out its puzzles and threats, and help to solve and eliminate them. The trouble here is that the puzzles are pretty obvious.

It’s a standard new Who formula, especially when Moffat’s involved: something goes bump in the night, but it turns out to be from space! Surprise! There’s only so much we can complain about this, however, since it’s exactly the same formula that dominated 70s Doctor Who, especially the Hinchcliffe/Holmes era, arguably its most popular and successful period before the BBC Wales revival.

The difference is that back in the day, the solution to the problem typically followed a raft of unpreventable deaths and involved cleverly improvised technology. These days it’s more likely to involve deaths that undo themselves like magic, followed by hugging and growing and learning.

Not that formula is unforgivable. As noted last week, stories driven by heart beat stories driven by surprise. Even if the formula means the plot’s obvious apart from a few details, it can still be moving. And it should be, but it isn’t, quite, even though the troubled boy’s father acts his socks off.

Maybe it’s that we’ve already been places more emotionally adult than this, such as Rose facing her own family traumas in “Father’s Day.” Maybe it’s that scriptwriter Mark Gatiss’s subtextual formula is as familiar as his textual one: boy represses his emotions (never cries, stuffs his fears into a cupboard), boy’s parents don’t understand, everyone finally learns that the shadows on the wall and scary elevator noises were standing in for concrete fears that kids aren’t supposed to know about (in this case, financial problems that lead to overheard conversations about whether they can keep the boy who doesn’t realize how desperately he was wanted), everyone hugs and grows and learns. If it’s not quite moving, though, at least it’s respectable.

Two complaints about the way these themes are presented: first, the Doctor twice insists that “monsters are real.” However, the entire point, the only way they can be defeated, is realizing that they actually aren’t. You might argue that they are real, that they’ve been created from fear and now truly exist, but the way the doll’s house and its effects simply evaporate at the end doesn’t bear this up. If this is enough of a gray area that it doesn’t matter, why make a point of it? Second, the Doctor tells George that only he can stop the monsters (he’s gotta “believe”), but in the end it’s George’s father who has to make the leap and soothe George’s fears.

The Doctor can be wrong (or senile, remembering the alien species he’s dealing with only at that point in the script where it’s dramatically convenient), the Doctor lies, but it seems a bit cheap to tease us that kids can defeat their fears through inner strength and then make George a largely passive victim all along.

So it’s not great, and there’s not much to it, but it looks terrific (maybe better than a lower-income apartment building should, but I’m not complaining) and isn’t particularly embarrassing. It’s a nicely self-contained episode, less ambitious than “The Curse of the Black Spot” but consequently less disappointing.

At first you might question whether the Doctor’s “house call” is entirely in character — in the past he’s typically fallen into the role his title implies, arriving as explorer or tourist and helping out because he can’t help himself. But remember that just two episodes ago (“A Good Man Goes to War”) he found out his name had come to mean “great warrior,” and that he might now feel compelled to try and change that. It’ll be interesting to see whether and how this plays out during the rest of the season.

Good moment roundup:

• George’s father suggesting that maybe scary TV or books gave George his fears, and the Doctor brushing these theories off. Mid-70s Doctor Who also saw a lot of controversy about whether the show was too violent and scary for young children; while I doubt they’re getting this kind of criticism today, it would have been a good response.
• The glass eye in a drawer, a perhaps unintentional callback to “The Eleventh Hour.”
• The sonic channels E.T., bringing George’s robot toys to life.
• The Doctor, trying and failing to solve the Rubik’s cube and tossing it aside: “Must be broken. Hate these things.”
• Amy and Rory (who are funny but mostly useless this time out) arriving in the doll’s house and thinking they’ve been killed by the falling elevator: “We’re dead. Again!”