Explain a little bit about Niska – how would you describe her character?

I would describe her as very vulnerable, actually. I think she’s probably one of the most vulnerable characters in it. I guess because of everything she’s been through, she’s reached a place of being naturally mistrustful of everyone and everything, and over the series has gradually learned, one synth and one person at a time, to trust. So she’s very vulnerable, but with a hard exterior that she uses to protect herself.

Is it fair to say she’s the most bad-ass of the synths?

I’d love to describe her as that, actually. She certainly gets the most action and superhero moments that are really fun to play. She is definitely pretty bad-ass.

Going back to the first series, how did you find the experience of going to synth school, and of playing a synth?

I can’t think of an experience I’ve enjoyed more, in terms of filming process. That initial planning stage that we had, where we had an amazing amount of rehearsal time, and time to develop the synth movement – you so rarely get that when filming. So it felt like a play that was going on to be filmed. And we had a real ownership of the movements, because we’d been part of the developments. It created a real cast feeling as well, which you often don’t get because you all arrive to film little bits on your own days, and you pass people in the make-up truck. So I loved all of that, and it definitely felt like we were part of the birth of something. And so then, when it was really successful and had incredible viewing figures, there as an even bigger element of pride and joy in the project, because we felt like we were really part of the process of it as well.

Now we’re on series three, can you slip quite easily back into synth mode, or do you have to go back to synth school for refresher lessons?

There’s still quite a process involved, I was surprised by how much work I had to do to get back into it this year. I’d assumed it would all still be left there. And once I’d done some work, it was all there, but I spent a couple of weeks before this season doing things at home in a synthy way.

So you were unloading the dishwasher as a synth?

Yeah, exactly. We don’t even have a dishwasher, so I washed the dishes like a synth. And things that are quite difficult to do as a synth, like putting your coat on – things that in a human take a thousand tiny movements, trying to do as economically as possible. And also walking down the street as a synth is my absolute favourite. I am someone who is always moving out of everybody else’s way, so to just force yourself to walk down the street in a straight line – obviously you move if there’s a pram or something – but that kind of thing is really interesting, and changes how you associate with your surroundings and other people around you?

Do you get strange looks?

Yeah, you do, because it does look different. But then you notice that there are people who do it all the time. You walk through the city, and there’ll be a guy in a really expensive suit who is just powering down the middle of the pavement with his briefcase, seemingly not noticing anything else. But going back to the preparation for this series, we also had Dan O’Neill on set every day. He ran a synth school for us, and he’s there every day, so you know that if there’s anything that you personally find difficult, he’ll be there to remind you to put it back in place. We all have something that we’re the least good at – mine is that I have a very swingy left arm, he’s always telling me “Your left arm is swinging around like a synth’s wouldn’t!”

At various points in the production you are a human pretending to be a synth who’s pretending to be a human. Does that get a little confusing?

This year has had that element much more than any other year, in the sense that she’s under cover for loads of this series. You’d think “Oh, well, just be yourself as a human,” but that’s not right. The easiest way to do it is to go full synth, and then choose a few things to add in that are human – so hands in pockets, or slightly place the weight onto one leg, which means you’re not totally centred in your balance. But also I think we had an idea this year that not only is Niska pretending to be a human sometimes, but that by being around humans so much and living with a human for a year, she might have organically changed a bit in a way that you or I would if we lived with somebody – you end up picking up things about them. She has become slightly less synthy in some very subtle ways. But that was a bit of a brain teaser at the beginning – how many layers can we get in here? It would have been good if she’d then had to pretend to be a human pretending to be a synth somehow. That would have been an extra challenge.
Were you ever pushing for the idea that the way you’d show Niska’s development is she can have a really loose left arm?

[Laughs] That would have been really good. I should have said “Maybe the choice she’s making is that she’s seen someone walking down the street with a really wobbly left arm and decided to incorporate that.”

The programme deals with the debate surrounding Artificial Intelligence – is it something you think about?
Yeah. Right from the beginning of series one I started to read into the area. I did a lot of scenes with William Hurt in series one, and it’s something that he’s really interested in, he was a great person to get articles from and so on.

He is terrifyingly intelligent, isn’t he?

Just on another level of intelligence! So I always thought “Right, if we’re going to be able to have good conversations about AI, I need to go off and read some articles so that I can bring something as well.” I got particularly interested in the fact that the main problem with the development of AI, in terms of looking for genuine artificial consciousness, is that we don’t know what consciousness actually is. So how do you create something when nobody genuinely knows what it is, what that spark is that changes something that looks like it is conscious to something that truly is conscious. Obviously a really convincing robot could tell you they were conscious, but that doesn’t mean they are. That’s the whole problem throughout Humans, with the synths having to prove somehow that they are in some ways the same as humans, and not just a really incredible copy. So that took me down a terrifying rabbit hole of going “Maybe nobody I know is actually conscious. Maybe I’m the only conscious being on Earth.”

If this technology was available, would you get a synth?

I’m saying no I wouldn’t, but as I’ve been reminded repeatedly, when everybody started getting mobile phones, I said I would never get a mobile phone, and as you can see, here is my mobile phone. And I said I would never get an iPad, and I’ve got an iPad. So I’d like to say I wouldn’t get one, but I have a horrible feeling that somewhere down the line I might.

You’ve all been together as a cast for three series now – what’s the experience like of working together?

I think we all agree that there’s nothing nicer than coming back to something where you know already that you really like everybody you’re working with. It’s hard sometimes as an actor, every time you start a job it’s like the first day at school all over again, where everyone is new and you are new, plus the work is new. So coming back to something where the people aren’t new, and your character isn’t new, is wonderful. We all get on really well, and we see each other out of filming, so when you get to see your friends at work, it couldn’t be much nicer than that.

If you could take one cast member home to be your personal synth, who would it be, and why?

It probably doesn’t make sense, but I’d probably take Odi, even though he’s broken. I just loved him, he was so sweet, and could just get me apricot jam on toast all the time.

The show is also shown in America – do you have a sense of how it has gone down over there?

I was in America when season two aired there, so that was a perfect opportunity to see what sort of impact it was having. Instantly I got off the plane and saw a massive billboard for it. And every meeting I had over there, and speaking to other actors, there was a really lovely reception for it – exactly the same as here. People are dealing with the same issues, of technology and what that means for us, and I think the sense of living in a place divided. If anywhere can understand that just now, it’s the UK and America. That theme of how we deal with a division of opinion in a country, and how dangerous that can be, it couldn’t be more timely.

You’re a very political person, and you’ve worked in parliament. What are the chances of you doing a Cynthia Nixon a few years down the line?

First of all, is Cynthia Nixon a pun, because it’s a very good one – Synth-ia?! Synthia Nishka. Maybe I could run as a synth? I don’t know, I think personally good politicians have to have far thicker skins than actors do, and I don’t know, yet, if I have that. I definitely feel really passionate about specific causes, and that’s something I’ll stay totally involved with.