A returning companion, a returning classic monster, and a plot built entirely out of satnavs. “The Sontaran Stratagem” is a solid, workmanlike first half — it doesn’t have the ambition of the season’s best, but it moves briskly, it brings Martha Jones back in a way that respects where she was left, and it lands a genuinely uncomfortable argument about the Doctor and the military. Also the Sontarans are enormous fun, which covers a multitude of sins.
Martha Jones, UNIT Officer
Martha walked out of the TARDIS on her own terms at the end of Last of the Time Lords, and the show has been sensible about what she did next. She’s finished her training, she’s a doctor, she’s engaged, and she’s working as UNIT’s medical officer — and it’s she who summons the Doctor, on her own authority, because something on Earth needs him.
That’s a good look for her. The Martha who left was hollowed out by a year of walking a conquered planet and by loving a man who wouldn’t look at her. The Martha who comes back is composed, senior, and completely over it. Freema Agyeman plays the reunion with real warmth and zero yearning, and the show is smart enough not to reopen the wound.
The best gag in the episode is Donna and Martha meeting, with the Doctor visibly bracing for a catastrophe that never arrives — the two of them get on immediately and start comparing notes about him, which is his worst nightmare. It’s a small scene and it does a lot of work.
There’s a nastier thread running under her return, though. The Sontarans take a copy of her — a clone grown in a tank, loaded with her memories, walking around UNIT wearing her face and carrying her clearance. It’s a well-worn science-fiction idea, but the episode wrings one genuinely good chill out of it: the sight of Martha’s own body suspended in a growth vat while her duplicate carries on with her shift two floors up, and not a single person in that building noticing the difference. That’s the horror of it. She’s one of the most capable people they have, and she’s been replaced by lunchtime.
ATMOS
The threat is a nicely mundane one. ATMOS is a device fitted to four hundred million cars worldwide: a satnav that also reduces exhaust emissions to precisely zero. It’s cheap, it’s ubiquitous, it’s in every vehicle on the road, and — as the Doctor points out with the weariness of a man who has seen this a hundred times — nothing that good is free.
Two things are wrong with it. The satnavs have started driving people into rivers, killing anyone who investigates the company too closely, which gives the first act a decent thriller pulse. And the emissions system is doing rather more than filtering. There’s something genuinely modern about the paranoia here: a piece of consumer technology, willingly installed by hundreds of millions of people, quietly turned into a global weapon by the company that supplied it. The show doesn’t labour the point, but it’s there.
The opening death is the best-directed thing in the episode: a man alone in his car, doors locked by a system he paid for and trusts completely, being driven calmly into a river by a pleasant female voice reading out directions. No monster, no ray gun, no warning — just a machine following its instructions while he hammers on the glass. It’s exactly the sort of small domestic horror this show does better than almost anyone, and it establishes the threat far more effectively than any amount of fleet-in-orbit spectacle manages later.
Sontarans and a Clever Boy
The Sontarans themselves are a delight. Squat, potato-headed clone warriors who bellow “Sontar-Ha!” in unison, who genuinely cannot conceive of a fight not being glorious, and who are lethally vulnerable to a well-aimed tennis ball at the probic vent on the back of the neck. General Staal — “Staal the Undefeated” — is played with tremendous relish, and the writing gets the joke exactly right: they aren’t stupid, they’re just so completely governed by their own warrior code that it can be used against them. A species that cannot resist a duel is a species you can manipulate.

Their human collaborator is Luke Rattigan, a teenage genius with a private academy full of gifted students and an ego the size of a small country. He’s an effective creation — a boy so convinced of his own brilliance and so starved of actual respect that a race of alien soldiers telling him he’s special is enough to buy his entire planet. He’s insufferable, which is the point, and there’s real pathos underneath it: the Sontarans obviously despise him and he can’t see it. His academy is a good detail as well — a country house full of brilliant teenagers he has personally assembled and cannot relate to for thirty consecutive seconds, every one of them visibly sick of him. Rattigan wants to be worshipped by people he’s decided are beneath him, which is precisely the lever the Sontarans use to pick him up and carry him about.
Soldiers
The most interesting thread is the Doctor and UNIT, and it’s genuinely prickly. He works with them and he does not like them. He bristles at the guns, at the salutes, at Colonel Mace calling him “sir,” at the whole apparatus of an organisation that solves problems by shooting them. Mace, to his credit, pushes back — these people are defending their planet, and the Doctor’s disdain for how they do it is easy to hold when you can leave whenever you like.
There’s no neat resolution offered, and the episode is better for it. Given what we watched him do to the Family, and the flames he stood in during The Runaway Bride, his squeamishness about soldiers is a rather more complicated position than he’d like it to be.
Meanwhile Donna goes home, and it’s the warmest material in the hour. She sees her mother, who is as deflating as ever, and her grandfather Wilf, who is thrilled. Since Partners in Crime the show has quietly been building the Nobles into the most grounded family the series has had, and Donna’s realisation that she can pop home whenever she likes — and that she’s been away three months by their clock — is a lovely, human beat.
Which makes the cliffhanger land properly. The ATMOS devices activate worldwide, gas pours out of four hundred million exhausts at once, and Wilf is sitting in a locked car in his own driveway with the doors sealed and the fumes rising. Somewhere in there is a Martha who isn’t Martha. And an entire Sontaran fleet is in orbit, delighted.
What The Sontaran Stratagem Leaves Us With
Efficient, entertaining setup with one genuinely thorny idea. Here’s what it plants:
- Martha, recovered. Back with a job, a rank and a fiancé, treated by the script as a professional rather than a loose end. Her exit is honoured rather than undone.
- The Sontarans, done right. Absurd and lethal in equal measure, with a warrior code that’s both a joke and a genuine weakness. Best classic-monster revival since the Cybermen.
- Consumer tech as the weapon. A free gadget in every car, installed voluntarily, weaponised remotely. Uncomfortably plausible.
- The Doctor versus the army. A real argument the episode refuses to settle, and one that’s harder for him to win than he thinks.
- The Nobles. Wilf and Sylvia keep the season’s feet on the ground, and putting Wilf in that car is a very effective way to make a global catastrophe personal.
Rating: 3/5 — Sturdy rather than inspired, with some clunky dialogue and a middle section that marks time. But the Sontarans are a joy, Martha’s return is handled with care, and the cliffhanger is a good one.
Four hundred million cars pumping poison into the sky, an old man locked in his own Vauxhall, and a fleet of very short soldiers who could not be happier about any of it. Part one done.




