‘This is a hoary old one. Talk about neglect.’ Back on Saturdays in 45-minute episodes, this could have been the opportunity for an exciting new phase of the show. Location filming on the streets of London, stylishly directed by Matthew Robinson, makes this look more like an episode of The Sweeney than anything the series has tried before. A gritty diamond heist that inadvertently uncovers a Cyberman invasion is a good hook. The opening of this is pure Season Seven: workmen being attacked by something monstrous; the Doctor and companion dashing about run-down looking urban locations. It’s an instant step up from The Twin Dilemma.

But – this isn’t a new beginning at all. After the opening scene, the action flips to the Doctor tinkering in the TARDIS and extended sequences of the Doctor reminiscing about Jaconda and a timid Peri worrying about what he’s going to do next and wittering on about the regeneration and how unstable the Doctor is. I think the moment when the Doctor laughingly promises his scared companion, ‘Don’t be afraid, I won’t hurt you’ is horrible – why would you have the lead of your family show say this? The lack of judgement and sense is staggering. JNT and Saward should have been working overtime to make up for the failure of The Twin Dilemma, not doubling down on it. Why ask Baker and Bryant to play it like they hate each other? Why ask Bryant, playing an American teenager, to deliver lines like, ‘On one occasion you even referred to me as Jamie’?

This is even more bafflingly incompetent when other parts of the script (mostly the bits that don’t involve the Doctor and Peri) are quite good. There’s a very funny joke when Lytton’s associate picks up a sledgehammer and mentions he used one when he worked for the council: ‘This time it’s for swinging not for leaning on,’ replies Lytton. ‘You said you came from Fulham,’ an outraged Griffiths (the brilliantly dry Brian Glover) says after Lytton reveals he’s from outer space.

The structure mostly works well too: the Doctor and Peri are investigating the crime that Lytton is about to perpetrate, and the great, mid-point twists that Lytton is searching for the Cybermen, and Terry Molloy is actually an undercover cop. There’s momentum and a sense of the Doctor inexorably walking into a trap. Fair enough, it relies on the audience only vaguely remembering Resurrection of the Daleks (the Doctor barely interacted with Lytton previously), and Robinson’s decision to have uniformed police officers in the Cyberman base unnecessarily suggests Lytton’s lackeys are actually Cyberman agents, but it has a through line that’s much more compelling than Saward’s previous script.

And then, Lytton mentions the Cyber Controller on Telos and the action flips there for astonishingly pointless and incoherently shouty scenes of Bates and Stratton, two characters who bear no relation to anything we’ve seen or heard so far, staging an escape from a work party. It’s a rubbish way to reintroduce the Cyber Controller, wandering round an unimpressive version of the Tomb of the Cybermen and flip flopping on whether to have Bates and Stratton killed. Far better to have held the location, and the Controller, back until Part Two.

Next episode: Attack of the Cybermen – Part Two