Sometimes, we get the best and worst of Doctor Who in one single episode. So come on down The Lie of the Land, which for me shows both those things in short order. It’s a tale of two scenes.

Let’s get the first and worst out of the way. It’s the most infamous scene in the story, and perhaps, in time, will become the most infamous in the whole of the new series. It’s the one where the Doctor (waspish Peter Capaldi) goads his companion Bill (Pearl Mackie) into shooting him, for no good reason.

The story goes that in a world subjugated by alien Monks, the Doctor has gone over to their side, issuing regular video sermons like it’s 1984. Bill is convinced he’s faking it and concocts a plan with fellow companion Nardole (Matt Lucas) to rescue the Doctor from the prison ship on which he’s being held.

(It’s easy to see why Bill jumps to that conclusion. Faking being bad is a standard Doctory ploy. And it’s not just that scenario which feels familiar. The whole episode, focussing as it does on what happens when the invaders have won and established a totalitarian regime, feels like a retread of The Sound of Drums/The Last of the Time Lords, complete with scenes of people being dragged from their family homes and towering statues of the dictators in question.)

Once Bill and Nardole arrive on the ship, they find their way to the Doctor’s office, but it appears they have made a critical miscalculation. The Doctor hasn’t been faking it. He really has given up and capitulated to the Monks. He berates Bill for causing the situation by asking the Monks for his sight back. He threatens to hand her over to the guards. For Bill, who has spent months fighting against the Monks’ mind control and struggling to hold on to what’s real, this is too much. Distraught, she snatches a gun and shoots the Doctor three times in the chest.

Which is when the Doctor fakes a regeneration, reveals the bullets were blanks and reverses his fake out. He was fooling her all the time. He’s not in league with the Monks. Nardole and everyone else in the room was in on it. He played out this macabre charade, because “I had to just check that you weren’t under the influence and testing me.” The end result is Bill humiliated in a room full of people, after her friend psychologically tortured her to the point where she attempted to murder him. For the sake of a cheap trick.

The Doctor faking that he’s gone bad is everywhere from The Invasion of Time to Mindwarp. And the Doctor breaking down his companions’ faith in him is equally common from The Curse of Fenric to The God Complex. But never before has the Doctor coerced one of his friends into murder. Sure, it’s an exercise in “how far can we take this?”, complete with an ersatz regeneration. But it’s not important to the plot, it’s instantly forgotten and it’s unnecessarily cruel. Bill never gets to redress this emotional abuse and humiliation. It’s the most poorly judged moment since the show’s return; the equivalent of the strangling in The Twin Dilemma. May we never see its like again.

But then – the second of these two remarkable scenes.

The Doctor and Bill realise they need some intel to help them beat the Monks so they decide to open the Vault and consult Missy (Michelle Gomez). There isn’t a Doctor Who story around which wouldn’t be enlivened by a scene with Missy and this one is straight out of The Silence of the Lambs, in which serial killer Hannibal Lecter is consulted by young detective Clarice Starling on how to catch another murderer. Like Lecter, Missy issues her advice from within a cell. She taunts and flirts with our heroes. She is, despite being caged, in complete control of the scene. One minute she’s a school mistress, circling her enclosure, correcting the Doctor’s faulty reasoning. The next she’s a vamp, rolling around on the top of a grand piano.

The Doctor and Bill have come asking for Missy’s help and she knows it. She starts with bragging that she could easily escape if she wanted to and then starts the horse trading. She wants a 3D printer and a pony apparently, but that’s a transparent lie. She already has what she wants. That’s the Doctor’s attention.

Better than that, the Doctor is going to be in debt to her and she can use that to her advantage. She’s correctly anticipated the situation and she knows that to defeat the Monks. Bill has to die. “Awk-ward,” Missy sing songs when she breaks this news to Bill, her steely eyes revealing that she knew this was where they were heading all along.

And it ends beautifully, with Missy pointing out that the Doctor doesn’t have a monopoly on virtue, and that the answers he seeks aren’t always easy.

MISSY: I’m sorry your plus one doesn’t get a happy ending, but, like it or not, I just saved this world because I want to change. Your version of good is not absolute. It’s vain, arrogant and sentimental.

And after watching the scene where the Doctor indulged in mental torture of his best friend, who could argue with the vain and arrogant part?

It’s a delicious, elegant scene. But it seems to me there’s so much untapped dramatic potential here. Imagine a better version of that first scene where Missy taunts Bill into defeating the Monks by shooting the Doctor. Or if the Doctor had indeed teamed up with Monk and Bill and Nardole had to release Missy to defeat him. Where might we ended up under these or any number of other scenarios? Not, I hope with an ending where the all powerful alien conquerors are defeated by a memory of Bill’s mum. Not since Azal was confused to death by Jo has a badass been defeated more bewilderingly.

I realise I’ve been a little more judgemental of this story than I am usually am in these posts. But as you might have guessed from my thoughts on Extremis, I find the Monk trilogy unusually frustrating. Clearly trying to do something new, but so clearly mired in what’s been done before. And in The Lie of the Land’s case, being muddled in tone and plot alike.

But then I remember that showrunner Steven Moffat was distracted at this time of script editing this by the death of his mother. Apparently, he was struggling to complete this episode as she passed away. That’s unspeakably sad and it goes some way to explaining the unevenness of this adventure. If there’s ever been an episode where we need to cut the Moff some slack, it’s surely this one.

Still, it doesn’t change the fact that The Lie of the Land is one moment clumsy and morally dubious, the next smart and stylish. I keep coming back to The Twin Dilemma. Like that infamous story, it leaves us with the queasy feeling that the companion is not safe in the Doctor’s presence, because at any moment she might find herself on the wrong end of his changeable morality. And that we as viewers aren’t in safe hands, in an episode which swings between such extremes of quality. With the good and the bad in such quick succession, it makes for an uneasy rollercoaster ride of a story.

LINK TO Carnival of Monsters: both feature Cybermen cameos.

NEXT TIME… Right then, troops. No, not troops. Team? Gang? fam? We end the year with the new Doctor in The Woman Who Fell To Earth.