In between his high-profile roles in Slow West, Steve Jobs and the forthcoming X-Men: Apocalypse, Michael Fassbender took time out to shoot a gritty new version of Shakespeare's Macbeth with Australian filmmaker Justin Kurzel. "While on a big film you've got all the options in the world open to you," he says. "But on a small film even getting it made is a hard thing. I love how fast you have to work - that pressure of having to get it right in one take or not at all." 

Marion Cotillard and Michael Fassbender in 'Macbeth'Marion Cotillard and Michael Fassbender have an emotional story to portray in 'Macbeth'

Fassbender's only previous experience with Shakespeare was in drama school. "Shakespeare is challenging because of the language," he says. "And Macbeth is going through quite a lot!"

More: Read our review of 'Macbeth'

Indeed, Kurzel wanted him to play the character as a victim of post-traumatic stress disorder. "When Justin said it, it was so obvious," Fassbender says. "Because it's actually in the play, in the banquet sequences. Lady Macbeth tells everyone to relax because she's seen this behaviour before, he's prone to fits. He's seeing Banquo and the witches in the same way that soldiers coming back from Iraq can be walking through Clapham Junction and next thing they're in downtown Basra." 

Watch the trailer for 'Macbeth' here:

Lady Macbeth is played by Marion Cotillard, who had the added challenge of performing Shakespearean dialogue in her second language. "It's hard," she says. "And while I have been through very deep experiences with many dramatic roles, this one was the darkest of them all. All the roles I've experienced have had some light in them. But here there was no light. Lady Macbeth is - well, she's a piece of work. I always want to abandon myself to my characters, but I was scared to enter the darkness."

More: Watch clips from 'Macbeth'

Clearly, Fassbender, Cotillard and Kurzel hit it off on the set, because they reunited last month in Malta to film an action blockbuster based on the videogame Assassin's Creed. 

Cotillard laughs about the shift from Shakespeare to a videogame. "Yeah, I don't know anything about the game," she says. "No offence to this game, but I cannot play a game where I have to kill people. I don't even know if they kill people. They do, right? Well, it is called Assassin's Creed!"

More: Michael Fassbender hopes to inspire schoolchildren with 'Macbeth'