It is Mark Gattis time on Doctor Who. Long time collaborator with Stephen Moffat both off screen and on screen (e.g. as Mycroft in Sherlock), Gattis has never written any truely stand-out episodes but has managed a few goodish ones (e.g The Unquiet Dead).
As episodes go, this one is almost the platonic ideal of a Gattis one. Victorian setting with some interesting twists (British soldiers on Mars in a steampunkish aesthetic), a classic “monster” (the Ice Warriors) but an otherwise conventional story.
The backstory (explained by the officers to Bill on Mars) is that British soldiers in SOuth Africa found an Ice Warrior spaceship with a hibernating Ice Warrior. Christening him “Friday”, the Ice Warrior transported the soldiers back to Mars and is helping them dig for treasure in the remains of the now extinct Ice Warrior civilisation. Of course things go awry…
Some obvious digs at colonialism and a by the numbers plot well executed.
The main squee moment being a late cameo by Ysanne Churchman as the eyeball-with-arms alien Alpha Centauri, from the classic “Peladon” stories from the third Doctor’s run. http://www.imdb.com/name/nm0161489/bio?ref_=nm_ov_bio_sm
Fun, but not great.