It's a moment that will be remembered for years after it aired – Peter Capaldi's iconic speech in the Doctor Who two-parter The Zygon Invasion/Inversion.


The scene, which sees the Twelfth Doctor (Capaldi) attempting to talk Zygon leader Bonnie, who has taken the form of his companion Clara (Jenna Coleman) out of starting a war against humanity, has undoubtedly gone down in Doctor Who history – both for the writing and the performances.

Chatting to ahead of his new novelisation The Zygon Invasion, writer Peter Harness broke down that epic moment.

He explained: "At that time, whenever it was – I think it was about 2014 or 2015 – before it felt that the world had definitely taken a dramatic turn for the worse, I kind of thought, 'If you meet somebody like that, if you meet somebody who's intent on kind of disruption and tearing everything down, is it possible to talk them out of their mindset? Is it possible to talk somebody who's so deeply entrenched in something out of their mindset?'

"I'm not entirely sure, six or seven years down the line, how easy that is anymore. But I thought that if somebody could actually do it, then the Doctor could.

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"As it unfolds in that episode, [The Doctor] has been to the same place as Bonnie has. He's been in the same room and made that same decision. And he just doesn't want anybody else to have to live with that.

"It came from wanting to know whether it would be possible for the Doctor to talk somebody back from the edge, just using an emotional, intellectual appeal. Clara is also inside Bonnie's head so that definitely has something to do with it but rather than ending it in a series of explosions or machines or punch-ups, I just wanted it to come down to conversation in a room about whether this is the way we want to go or not.

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"Of course, [Capaldi] sold that intensely well with his performance but it was a long scene on the page and I was very happy that it paid off. That's the speech that Steven Moffat and I batted between the two of us until it felt that it was just right and I think [Capaldi] delivered it just right.

"Watching it as a viewer, it felt like one of the first moments from Peter Capaldi that you could define his Doctor by. I think it's one of the moments of that era that people remember and I'm really proud to have been a part of making that."

As for whether there could ever have been a different ending to that episode? Harness doesn't think so.

"I think [Bonnie] was always going to get talked back from the edge. Otherwise, we would have just had to shoot her and that would have been OK but it would have been a bit boring. It was always, can the Doctor talk someone round? Can he talk someone back from the brink?"

The writer is also no stranger to criticism from fans. After all, he wrote the divisive episode Kill the Moon. But he stands by everything the Doctor says in The Zygon Inversion.

"I can't think of anything I would change about the Zygons," he reflected.

"I know the Zygons also have some political aspects that are a little bit on the nose and a little bit uncomfortable but I still stand by, essentially, what the Doctor says – that whatever grievance you have with somebody else and whatever battles you're fighting, no matter how terrible somebody has been to you and how unjust things have been, that the only way to stop it destroying you completely is reach some form of accommodation or forgiveness about it.

"That's a very hard truth to acknowledge and maybe it's not right to expect Bonnie to be at that stage but I think the Doctor in all of his wisdom and all of his experience with conflicts knows that, eventually, after all the shooting's done and all the hurt has been inflicted and all the pain's been through, you've got to sort it out in a different way."

The new novelisation is the first time Harness has returned to Doctor Who in quite some time, with the writer recalling watch-alongs during the lockdowns in the UK.

"I hadn't been on social media or anything at the time of the Zygons because it can be quite good to hide away from those things when your episodes come out so I didn't really know how they'd gone down. But it was a lovely experience and a very warm experience in a bit of a dark time for everybody. And it was very nice to watch those episodes again and see people's response.

"So I was back in that mindset again and I think it was around about then that they asked about doing a Target book... I thought I cannot possibly not do a Target book because those were the books that, like so many others, taught me how to read and gave me a real love of books."

The Zygon Invasion by Peter Harness (BBC Books, £9.99) publishes on 13th July – pre-order a copy here.

Doctor Who is available to stream on BBC iPlayer with episodes of the classic series also available on BritBox – you can sign up for a 7-day free trial here.

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