Mara explains the plot: "Well, from my character Lee Weathers' point of view, it's about a risk-management consultant who's hired to assess whether or not this artificial being named Morgan [played by Taylor-Joy] is too dangerous to keep alive, and whether it and the project should be terminated after it attacks one of the researchers. It's science-fiction, and a thriller and an action movie."

Kate Mara starring in Morgan

The action aspect was important. "There was a lot of physical training for me and Anya before the shoot," Mara says. "[Director] Luke Scott is a boxer, and he's very passionate about it. He suggested that I take up boxing for this character, to get into that athlete mentality. And then he also wanted me to be able to do ballet and pilates! It was to balance the sort of feminine and masculine sides of the character. Then, when we went to Ireland, we were trained with weapons. We drag raced at one point, because I have to be able to drive really well for a chase scene. And then there were weeks of stunt training as well. So it was more prep than I've ever had to do for a role."

For Taylor-Joy, the challenge was learning mixed martial arts. "I come from a dance background," she says, "so the real thing for me was to turn myself from being a dancer into being a fighter. I definitely noticed the difference when that happened. We both trained a lot. We trained for two weeks before filming, every single day. It was kind of like a boot camp. And then we had an unbelievable stunt team!"

While Mara spent a lot of time on her own to get into the mindset of her loner character, Taylor-Joy craved social contact after hours during filming in Belfast. "I was very isolated on set," Taylor-Joy says. "I needed human contact at the end of each day. I got close to the crew and so I hung out with them a lot. And I love Irish people!"

Mara admits that seeing Taylor-Joy socialising got her out of her shell: "By the end, I was definitely letting myself do that a bit more."

Still, it was the Morgan's outsider mentality that resonated most with Taylor-Joy. "I very much understand what it is to not fit in or belong somewhere," she says. "I think, probably, the place that I feel I most belong is a movie set!"