At the beginning of this episode, the Doctor turns off some key TARDIS defense systems so that Clara can more easily fly the ship. That would also be a good time for you to turn off your brain so you can more easily enjoy the episode.

Except I'm not even sure that would do the trick. I think I'd sum this one up as a short list of "nice, but" elements:

• Seeing non-white characters in major guest roles is nice, but I'm not sure casting them as unscrupulous, unlawful, and frankly unintelligent working-class salvage merchants was a great idea.
• Seeing more of the inside of the TARDIS is nice, but since the corridors are plain enough that they could be the set of any spaceship anywhere, there's really no sense of wonder about it.
• Seeing the Doctor finally spill the beans to Clara that he's seen two versions of her die before (arguably three, now) is nice, but since he hits the (literal) reset button at the end of the episode, it doesn't really matter and doesn't tell us anything we didn't already know.
• Seeing the book of the history of the Time War is nice, but we don't learn anything from it except that his name is definitely not "the Doctor". (And who wrote the book? The Doctor himself? If so, and if it's such a big secret, why is his name in there at all, and who left it out on a plinth for anybody to skim? The TARDIS herself?)
• Seeing the Eye of Harmony was nice, but really, if having this piece of lore explained in probably the most reasonable terms we've heard in the series so far is what you were looking forward to, you are a sad individual.

It never got above "nice" for me in this episode, and beyond what I listed above, not much else even hit that mark. A lot of it was frankly dreadful (the less said about the "zombies" the better). As with Stephen Thompson's earlier misfire "The Curse of the Black Spot," I thought occasionally that there might be a good episode in here struggling to get out, but that Thompson had kept a firm lid on it.

Speaking of keeping a lid on it, if there's anything like a theme in this episode, it's to do with secrets, specifically those involving identity. Who is the android? What's the Doctor's name? What are the (ugh) zombies? And what is the deal with Clara? Well, of course we don't learn the Doctor's name in this. We'll have to wait for the season finale to get into that.

Classic series watch If you were excited this week because we were finally going to see the inside of the TARDIS!!!, you either haven't seen the classic series or your memory cheats.

It's not just that we've seen it before; it's that seeing more of the TARDIS typically isn't as cool as you'd think. I mean, this is a good time to remember that the TARDIS isn't real, and the insides of it are only going to be as interesting as the designer and writer can think and afford to make them.

In theory that's "very," but in practice, not so much. Let's look at the two best examples. "Castrovalva," the Fifth Doctor's first adventure, saw two episodes in which a regeneration-addled Doctor and his young companions wandered around pretty much identical corridors panelled in white recessed circles (the term is "roundels"), marking their paths with lipstick and yarn, eventually finding the Zero Room, a recuperative isolation tank whose main virtue is how utterly featureless it is.

I love "Castrovalva," and for me the TARDIS-bound episodes are riveting, but let's face it, all of that comes from the leads' performances and none of it comes from any inherently fascinating qualities of the interior TARDIS space.

The other time we've really explored the TARDIS interior was "The Invasion of Time," in which a Sontaran squad chased the Fourth Doctor around and around inside his own ship. On the one hand, we did see some interesting and incongruous rooms like the swimming pool and an art gallery; on the other, since the budget was low, most of these looked like disused institutional buildings from the 70s (because in fact that's what they were).

This isn't as featureless as "Castrovalva" or as cheap-looking as "The Invasion of Time," but there's really nothing here that inspires wonder; we go straight to fear. We've had a spaceship powered by an ocean in "Dinosaurs on a Spaceship," and a couple seasons prior to that, we've had a ship with a forest on board ("Flesh and Stone"). Shouldn't the TARDIS at least be more marvelous than that? Even the sheer drop in the engine room is just an illusion.