After the Extremis trilogy aimed high and fell short, it makes sense to do something smaller and more straightforward as a little palette cleanser. Empress of Mars sees the definition of ‘fanboy’ writer, Mark Gatiss, being unashamedly fanboy-ish as he brings together the Ice Warriors, Tomb of the Cybermen , John Carter and pretty much the early days of science fiction into one story. Upon seeing ‘God Save The Queen’ written on Mars, the Doctor and crew investigate. There, they find a platoon of Victorian British soldiers, aided by an Ice Warrior called ‘Friday’, trying to find resources in the bowels of the Red Planet. Of course, they stumble upon the ‘tomb’ of the Ice Queen, and things go very quickly pear shaped.

While it won’t win points for originality (indeed, it feels like a refined take on Cold War) or tremendous complexity, that’s almost not the point: Gatiss has deliberately written a love letter to the pulp era of fantasy fiction that does also offer some commentary on the culture that spawned it. What could’ve been just another ‘us vs them’ story, like so many Silurian tales, is given some weight thanks to drawing parallels between the two sides, and let’s face, how could you not? Both are ardently militarist, proud to a point of stubborness, have very strict structure and abhor cowardice in any fashion, seeing it as an ultimate brand of shame. This helps add some small but welcome shades of grey to the proceedings, and allows you to empathise yet also be slightly intimadated by both sides.

It also means, for the first time in a good while, that we get some dimension to the supporting cast, and even one of them has a character arc. We do get some distinct personalities and backstory for both the soldiers and our two key Ice Warriors, as well as a bit of a journey for the Colonel, Godsacre. He faces up to past sins and must ultimately prove himself as worthy of his mantle to the Queens of both worlds, and his climatic scene is rather moving.

Our regulars do as good as usual, with Capaldi getting some terrifically understated material as he is forced into the role of peacemaker, though the guest cast isn’t too shabby. Adele Lynch is great as the Ice Queen Iraxxa, beaming a sense of pride and regality under all the makeup and armor, while Ferdinand Kingsely chews scenery as the epitome of every stuck up ‘Jolly Ho’ colonial officer, Catchlove (am I detecting a little wink to Flashman?). Anthony Calf, as the Colonel, does create a geuninely sympathetic yet proud man, and similar props to Richard Ashton as Friday in creating a sympathetic Ice Warrior.

The episode also looks great: the vistas of the frozen planet, the cavernous interiors that radiate red, the crystaline hive of the Ice Warriors and their Queen, it’s like a hybrid of John Carter and the Universal Mummy films. The Ice Warriors themselves are also spotless, their terrific makeup and reptilian costumes aided by Wayne Yip’s low lighting and use of shadows to give them a sense of power and menace.

Empress of Mars is a distilation of everything that Gatiss is as a Who writer: he’s a geek who loves to show off his nostalgic passions, but with a definite earnesty that enables it to be charming. Even if it does suffer from the slight bit of rushing that afflicts all the single stories, it backs it up enough with some decent characterisation, setpieces and some smart writing. If this is to be his final script for the programme, then he’s definitely gone out on a fun one, and sometimes, the ‘fanboy’ is preferable to the ‘try-too-hard’ (Sleep No More much…).