‘I’m stuck on Earth like, like an ordinary person. Like a human. How rubbish is that?’ This one has lots of good bits, but the routine tidying up of The Sontaran Stratagem’s plot threads is oddly perfunctory and disconnected (for example, the NATO missile strike might have somehow played into the solution but is instead just dropped when it’s no longer relevant). Each one gets a scene to tie it off, then it’s on to the next item on the list. The result is a collection of scenes rather than a compelling story.

Some of those scenes are very good. I like the Doctor’s suspicions of Martha Clones becoming apparent when she admits to not checking up on her family or fiancé. I particularly like Wilf comforting his little girl Sylvia as the world ends around them, a moment of honest emotion in between several rather more forced sequences (like Martha meeting her duplicate and getting a little pep talk about how wonderful she is). I like the UNIT counter-attack, proving Colonel Mace isn’t the weak link he seems to be. And I like Donna’s impatient waving away of the big key-giving moment, and her adventures on board the Sontaran ship. I really like the “War Martha” version of her theme.

I’m not much of a fan of how this plays out, though. The Doctor’s rescue of Martha Jones disables the clone, and that plot ends. UNIT reclaim the factory and prove they’re still up to the job, then that plot ends. Luke’s herrenvolk have no interest in validating his delusions, and that plot ends with Staal briefly regretting he didn’t get to shoot them. At least their experiments in terraforming offer a solution to the poison sky, however implausible a little outdoor heater creating a worldwide fire might be. After his humiliation, Luke’s desperate desire to prove himself to be clever, could be read as an Adric moment, as he sacrifices himself making a point. Fair enough, although it just means he joins the long line of patsies who’ve jumped in front of a bullet at the last so the Doctor can walk away.

Ultimately, this is a fun two-part story, a memorable reintroduction for the Sontarans – the best thing about it – and the new series’ tribute to Action by Havoc. It some of it seems a bit cursory, I think that’s at least in part because we’ve already seen several similar Earth invasions, and this is a step down from the Series Three finale.

Next Time: The Doctor’s Daughter