The first part of the episode focuses on a bizarre cul-de-sac subplot featuring Jamie’s being kidnapped and then rescued in short order by two minor characters – Ruth Maxtible’s fiance the foppish Arthur Terrall, and his hired stooge Toby – who looks like Bill Sykes. It adds to the sense of Victorian melodrama, but hardly helps advance the story.

The Daleks are a bit more forthcoming about their designs: they want the Doctor to isolate the Human Factor and implant it into three dormant Daleks transported from Skaro, to help conquer humanity. And only Jamie will do – because of his experiences with the Doctor. Reinforcing the sense of cosmic wrongness implied by Waterfield’s description of the ‘horrors of time travel’, the Daleks tell the Doctor he has ‘travelled too much through time. You are more than human.’

That horror is also emphasised in the look of the episode: gothic secret passageways with deadly traps, flickering candle light and Waterfield’s Hammer Horror laboratory of bubbling vats amongst the oak panelling.

Whitaker is good on re-stating the stakes: we get another brief glimpse of Victoria, being transported to her new prison, and we meet Maxtible’s man Kemel, who is all kinds of problematic but essentially boils down to a dangerous opponent for Jamie. And the Doctor gets to pithily summarise the upshot of it all:

THE DOCTOR: It means the creation of a race of super Daleks

The real meat of the episode lies in the Doctor’s confrontation with Jamie, who has overheard some of all this. After their easy double act across the last eight episodes, the antagonism here is troubling, and all adds to the season finale feel of a rift opening between the lead characters. Jamie is at his most clear-headed and determined as he reminds the Doctor that a man has been murdered, and the Doctor is colluding with his killers.

The Doctor, however, brushes this aside: his manipulation of Jamie, subtly directing him to do exactly what the Doctor needs, is exactly the kind of thing the seventh Doctor will do to Ace. But it’s even more upsetting because the Doctor seems to partly enjoy the subterfuge, boasting of ‘adding a little fuel to the fire’ and congratulating Waterfield on his own part in the duplicity. This is a darker side that we haven’t really ever glimpsed before, and it makes the Doctor dangerous and unsettling in a way he hasn’t been since The Highlanders.

Next episode: The Evil of the Daleks – Episode 4