Picking up on that brutal cliffhanger from Rise of the Cybermen — the Doctor cornered, the party surrounded, that flat steel voice promising to delete everyone in the room — “The Age of Steel” had a lot to deliver. And it does. This is the half of the two-parter where the pieces that spent last week clicking into place finally go off, and while there’s plenty of running and shooting and factory-storming, what makes it stick is a genuinely upsetting idea at its centre, and the completion of an arc that’s been building for half a season. This is the episode where Mickey Smith stops being the tin dog for good.
Escaping the Trap
The escape itself is a nice bit of business — the Doctor produces the TARDIS’s last power cell and blasts the Cybermen with raw energy, and the survivors scatter into the night. From there it’s a race to Lumic’s Battersea factory, with the Doctor, Rose, Pete, Mickey and the Preachers converging from different angles on the place where the “upgrades” are happening. Lumic himself, meanwhile, gets a nasty comeuppance dressed as a promotion: his failing body finally gives out, and his own Cybermen forcibly convert him into the Cyber-Controller, the very fate he designed for everyone else. The man who wanted to escape death by becoming steel gets exactly what he asked for, and hates it.
Then Lumic springs his masterstroke. Every EarPod in the city activates at once, and all across London ordinary people go blank-eyed and start walking — a silent, orderly procession of the controlled, filing toward the conversion factories in their thousands. It’s a chilling image, and it pays off every ominous thing the first episode planted about a population that handed its attention over without a fight. Rose’s mother is out there in the crowd. Everyone’s is.
What follows is a proper assault, and the episode splits its heroes up smartly so that everyone has something to do: the Doctor and Mrs Moore go in low through the freezing access tunnels beneath the plant, Rose and Pete bluff their way in from above wearing deactivated EarPods, and Mickey and Jake take to the air in a stolen zeppelin. It gives “The Age of Steel” a real forward momentum after the deliberate slow-build of part one, and because the team is scattered, when things start to go wrong — and they go wrong for very nearly everyone — the losses land on people we’ve spent two episodes coming to care about.
The Horror in the Steel
Here’s where “The Age of Steel” earns its keep. For all the metal-monster spectacle, the episode’s real weapon is a single, awful idea: the Cybermen are people. Every one of those steel shells has a human brain trapped inside it, and the only thing keeping each of them from screaming is an “emotional inhibitor” — a chip that switches off the horror of what’s been done to them. Take a moment with that. They aren’t robots. They’re victims, anaesthetised against their own existence.
The show drives it home in the episode’s best and bleakest scene. The Doctor and the brilliant, brave Mrs Moore corner a dormant Cyberman and switch off its inhibitor — and it turns out to be a woman named Sally, converted on the eve of her wedding, still asking about her fiancé, still cold because she’s “getting married in the morning.” She realises, in real time, what she has become, and the grief of it kills her. It’s horrifying in a way the show rarely attempts, and it hands the Doctor his solution at a terrible price: Mrs Moore is murdered by a Cyberman moments later, one more good person lost to Lumic’s machine.
The Doctor works out that the inhibitor is the whole game. Shut it off everywhere at once, and every Cyberman in the city will wake to the full horror of its own body and be destroyed by it. It’s a solution that doubles as a mass mercy killing, and the show doesn’t pretend otherwise — the Doctor frees these people the only way left to him, and it’s the saddest kind of victory. Tennant plays it with no trace of triumph — just a man doing the necessary, terrible thing because no one else will, knowing exactly what it costs. It’s the same cold resolve we glimpsed beneath the charm when he faced down the Sycorax in The Christmas Invasion, turned here toward an act of grim mercy.
Mickey Smith, Hero
And the person who makes it happen is Mickey. The arc that’s been simmering since he named himself the tin dog in School Reunion pays off completely here. He watches his own parallel double, Ricky, die at the hands of the Cybermen — a gut-punch that could have broken him — and instead of folding, he steps into the gap. He takes the wheel, hacks into Lumic’s systems, pilots a zeppelin, and ultimately cracks the code that broadcasts the cancel signal to every inhibitor in London. The spare part saves the world. The man who was always told to wait in the car is, when it counts, the cleverest and bravest person in the building.
What lands even harder is what he does next. With the Cybermen beaten and Lumic fallen from his burning factory, Mickey chooses to stay. There’s a version of his beloved gran alive on this world, and a fight still to finish alongside Jake, and — crucially — a place where he is needed and seen, rather than trailing after the Doctor and Rose as an afterthought. His goodbye is understated and quietly heartbreaking. He’s not being left behind this time; he’s choosing to stay, on his own terms, as his own man. The friendship he strikes up with Jake — spiky at first, then real once shared grief over Ricky welds them together — gives Mickey something the Doctor and Rose never quite managed to: a partner who genuinely needs him. By the time he waves the TARDIS off, you completely believe he’s found where he’s meant to be. After a season of watching him ache to matter, it’s an enormously satisfying send-off.
Rose’s farewell is rougher. Pete Tyler — this world’s Pete, who never had a daughter — can’t cope with what she represents and simply walks away from her, and there’s nothing she can do but let him. It’s a cold little echo of everything Father’s Day put her through, a second version of her dad slipping through her fingers.
What The Age of Steel Leaves Us With
A muscular, moving finale that turns a monster runaround into a tragedy. Here’s what it plants:
- The Cybermen’s real horror. Not killer robots but converted people, screaming behind steel until a chip silences them. It reframes the monster entirely.
- Mercy as a weapon. The Doctor’s win is to let thousands of trapped minds finally feel what happened to them — a rescue that’s also a mass death, and the episode has the nerve to sit in that discomfort.
- Mickey Smith, fully grown. The tin dog becomes the hero and then walks his own road, choosing to stay behind not out of defeat but out of purpose. One of the best companion arcs the show’s told.
- Lumic gets what he wanted. The prophet of the upgrade is upgraded against his will — a tidy, grim piece of poetic justice.
- Another Pete, another goodbye. Rose loses her father all over again, and this time there’s no saving him — just the quiet cruelty of being unrecognised.
Rating: 4/5 — A strong, emotionally intelligent resolution that mostly justifies the slow build of part one, anchored by the horror of the inhibitor scene and a career-best turn for Mickey. A little of the factory-storming is standard-issue, but the heart of it is anything but.
The Doctor and Rose step back into their own world one companion lighter, with a hard conversation waiting for them at home. Mickey Smith stayed behind, a hero. Who saw that coming back when he was the bloke minding the phone?