Both Fassbender and Alicia Vikander were drawn to the project for different reasons, and they first met during the rehearsal process. "It was interesting to play a character like Isabel because it's hard to judge her," Vikander says. "As an actor, I felt that this was the most intimidating thing I've ever performed because it's so primal."

Alicia Vikander and Michael Fassbender in The Light Between Oceans

For Fassbender, the character just seemed like a perfect fit. "I sort of found the right emotional place," he says. "I felt that it was a really beautiful story. There's not a villain and a good guy, there's just regular people trying to sort of do the best they can in these circumstances. It's a beautiful love story as well."

In this kind of setting, Vikander says that becoming a couple off the set felt natural. But neither of them likes talking about it. "I think we've made a clear statement that we keep certain things just between us," she says. "It was very easy to unite, but that's quite personal. I love the mystery behind it all."

Both actors continue to be very busy with a variety of projects. And of course Fassbender has two big movies coming up. Assassin's Creed is gathering a lot of attention ahead of its opening later in the year, and as a producer he's involved in finishing it up. "We're still working on it, we're still editing away," he says. "I've been involved in it from the ground up, for five years now, so I'm really passionate about it. But you know, I feel like we've got definitely something very original and thought-provoking in this kind of genre."

And then there's Alien: Covenant, the Prometheus sequel in which Fassbender will reprise his role as the dispassionate robot David. "I have to say, this Alien is going to be - I'm really excited to see it," he says. "Everybody in the film was saying that this is a movie that we all want to see. It's much scarier than Prometheus, but it's got that sort of same scope as Prometheus, that imminent sort of disaster feel, that Alien had. So it's kind of a beautiful meeting of both of those films. I'm really excited to see it, I think it's gonna be super scary, number one."

Watch the trailer for The Light Between Oceans: