It probably works to the serial’s advantage that this wasn’t conceived as a Dalek story, and so the plot isn’t reliant on wheeling on the knackered old props for a “best of” turn. Instead, they’re again kept largely in the background of this episode, a malevolent presence, clearly calling the shots but largely from behind the scenes. It gives everything else space to breathe including Aubrey Woods (with the same silver face he has in Blake’s 7 – or maybe he just had a silver face) establishing himself as the oleaginous Controller, and maintains the sense of intrigue.

While we don’t exactly know why the guerrillas want to change history, it’s a pretty powerful motivation that, surprisingly, hasn’t been attempted seriously in the series to date. And although they remain antagonistic, the audience is given some clear indication that they’re actually goodies: they’re fighting the Daleks and Ogrons; their leader, Anat, is a reasonable woman, and, most importantly. the Doctor isn’t yet prepared to judge them harshly.

Two episodes into Season Nine, and Pertwee’s performance seems to have relaxed. He seems much more at ease that he did in chunks of Season Eight, giving the Doctor a sense of unflappable dignity even when he’s being escorted into a cellar and tied up at gunpoint. I’m not convinced by him picking up a ray gun to shoot Ogrons, but he looks great doing it. He’s no longer continually on the verge of bristling with indignation. Weirdly, this feels much more like his Season Seven interpretation.

But while Pertwee gets back in the groove, the Daleks aren’t quite right. There are the voices, so notably off they were re-done by Nicholas Briggs for the Special Edition DVD. But there’s also the movement – the 1960s Daleks constantly twitched and shuffled, as if buzzing with nervous energy or suppressed rage. Here they’re very static, motionless unless they’re talking. In some shots they might as well be empty casings. As the same operators are inside, this is either directorial choice or – as with the TARDIS materialisations in Colony in Space – time’s passed and they’ve forgotten how to do it. Still, we get the second ‘Exterminate!’ cliffhanger in a row, so some things remain consistent.

Next episode: Day of the Daleks – Episode Three