N.B. there might (or might not) be spoilers in this article!

Although The Sontaran Stratagem / The Poison Sky is perhaps the closest in style to “classic” Doctor Who we’ve had yet, as UNIT stories go, it feels more like yer Android Invasion than yer Green Death.

That’s not to disparage the merits of either as stories; it’s more that it doesn’t feel quite as though in The Sontaran Stratagem / The Poison Sky that we have all the ingredients of a UNIT “family” yet. That may be deliberate: the Doctor is even less enthused about working with UNIT here than he was for the first half of the 70’s. (Or was it the 80’s?)

With the Brigadier “stranded in Peru”, we’re left with a Colonel Mace as his stand-in — someone of military authority for the Doctor to be grumpy towards. Didn’t The Android Invasion have a certain Colonel Faraday as our Brig-surrogate?

What’s more, like that earlier story, there’s even a duplicate copy of a companion swanning around! I like how the Sontarans even took the time to pinch Martha’s jewellery. Nabbing her engagement ring — now that shows attention to detail in their planning!

“Know what you are? A great big outer space dunce.”

Donna, The Sontaran Stratagem

Elsewhere, Donna gets to go home and there’s a lovely scene where Wilf and Sylvia realise that they’ve both met previously (and separately) the person she’s been off travelling with (with a tidy bit of retconning to explain Wilf’s absence from The Runaway Bride).

There’s another barely liminal appearance of Rose on the TARDIS scanner and, by the end of this two-parter, with the TARDIS hijacked by some unknown force, the Doctor’s disembodied hand is bubbling away in agitation as well. So what’s all that about? Thanks to said hijacking, it seems as if Martha’s getting at least one more trip in the TARDIS, whether she likes it or not!

Overall though, The Sontaran Stratagem / The Poison Sky is as solid a slice of traditional Doctor Who as you could ask for.

These are my potential Target Library titles for The Sontaran Stratagem / The Poison Sky:
— Doctor Who and the Sontaram Strategem
— Doctor Who and the Poison Sky
— Doctor Who and the Sontaran Invasion of Earth