This is an episode that lives or dies on whether you can accept the premise. That is, that the moon is in fact a fertilised egg for a dragon-like creature. You also need to accept the science (or lack thereof) that goes with that concept. For example, if the moon is in fact an egg for an alien species, then why wasn’t it always 1.3 billion tonnes heavier? I mean how did the embryo go from weighing nothing to weighing a shitload more in what appears – going from the story – to be a short space of time? And who, or what, fertilised this egg? We see the “baby” lay another moon at the conclusion of the story. Does this mean that the egg is self fertilised? Or is the male of the species going to come flying along some point to add his genetic material to the moon?

So, like I said, if you’re willing to let questions like those above fly – probably by sticking your fingers in your ears and screaming LALALALALALALA – then there’s plenty to like and love about Kill The Moon.

For one, the first twenty minutes is genuinely dark and scary. Murray Gold’s music has been toned down, which means there’s no musical cues to key us in that something nasty is about to spring from the darkness. And the spiders on display here are fucking nasty. Probably the scariest looking monsters in living memory. The scene where Courtney is trapped with one of the spiders is horrifying in the sitting on the edge of your seat sort of way.

And there’s the moral dilemma that lies at the heart of the story. Once you’ve got past the bug fuck insanity of the moon being an egg, there’s the sobering realisation that the only choice for Earth is killing this creature before its born. The fact that the Doctor leaves humanity to make this decision for themselves is a brilliant moment – and completely unexpected and yet so very much like this Doctor. It does mean that the next fifteen minutes becomes a bit of a gabfest as Clara, Courtney (who steals the episode) and Lundvik heatedly discuss whether to detonate the nukes. Hermione Norris is excellent here giving these scenes the moral weight they need. (I understand that some have seen this scene as a debate between pro choice and pro life, as a result they’ve found the final decision to be tasteless. I’m not sure I buy the interpretation, given that the life cycle of this creature is so very alien. But I also admit that I might be missing something here).

The second half of the story isn’t perfect though. The bit where Clara asks the Earth for its opinion is very NuWho its silliness, also undercuting the debate between Lundvik and Clara. I’m not even sure how Clara could have seen the whole planet in 30 minutes. Putting the science of moon eggs aside, this is the weakest point of the episode.

Also, the spider monsters are mostly forgotten in the second half. There’s at least two shots of them crawling across the face of the moon, but in the 40 minutes that are left to Clara and co, they never seem to reach the base, which seems a little convenient. Having said that, it’s pretty hard to have a moral debate when you fighting off a horde of moon spiders.

But this is all a minor irritant when put against the TARDIS scene between Clara and the Doctor. It’s been along time coming and the argument played here – is the Doctor a patronising git or was he genuinely trying to help by leaving the decision to humankind? – is played perfectly. Yes, the Capaldi Doctor is abrasive and aloof and cold, but in his mind he was genuinely helping. Clara can’t see this – the line “is music playing in your head when you say these things” is both funny but very apt – and she makes the very good point that given how many times he’s saved the planet, it’s a bit rich for him to turn his back on all them now.

The episode ends with this agrument unresolved and the next week trailer – which looks a bit crazy as well – does its best not to show shots of Clara.

Overall, I mostly loved this episode. It’s crazy and insane like good Doctor Who should be and it also pushes the characters in ways that makes for good drama. Yes, the science is complete crap, but I’m willing to forgive it for an episode this crazy and bold and interesting.