When Ridley Scott announced that he was making a sequel to 2012's Prometheus (which itself was a prequel to his 1979 classic Alien), the one sure thing was that Michael Fassbender would be back as the android David. And in Alien: Covenant he also plays the newer-model robot Walter.

Michael Fassebender In Alien CovenantMichael Fassebender In Alien Covenant

Fassbender is a fan of Scott's approach to creating this epic franchise. "What's great about Alien: Covenant is the marriage of the first Alien film and what we did in Prometheus in terms of the scope," he says. "The horror elements are definitely there and, so once it gets going, it's relentless! Ridley wanted to bring in the disaster feel from the original film. He intentionally went back to his roots, and I think because of that there is so much here for the fans to enjoy."

Playing two roles made it enjoyable for Fassbender as well. "The characters of Walter and David are so fun to play and so different. David is very expressive and a big character. I put some Bowie influences in there, and with Walter he's more Gary Newman. I loved it. Then I think Walter's a different kettle of fish. David was definitely a work-in-progress, somewhat of a prototype I suppose. The elements of him that were the human elements I think people found a little disturbing, so Walter's more of a straightforward robot. Pretty logical, much more of a servant without the ego."

Fassbender says that in addition to finding a distinct voice for each character, he also had to discover their individual physicality. This is much more evident in David, as he has lived on his own for 10 years since the events of Prometheus. "Basically, I just watched a lot of Lawrence of Arabia," Fassbender says. "Because he was into that in the first film, I just kind of worked on that tone. I wanted to keep that consistency. And to sort of imagine I suppose that it fit quite nicely for the idea of a synthetic voice and body. I was listening to HAL as well [from 2001: A Space Odyssey], then I watched Blade Runner, and I did think about Ian Holm [in the original Alien], and how they were very naturalistic sort of robots. But I wanted to make it very clear that it was a robot from the get go in Prometheus. And it's the same in this one."

Watch the trailer for Alien: Covenant: