How Mahershala Ali tackled twin roles in the moving sci-fi drama Swan Song

In Swan Song, Mahershala Ali shares the screen with his trickiest scene partner to date: himself. The 47-year-old actor takes on twin roles in writer-director Benjamin Cleary's meditative future drama, playing both a dying man (named Cameron) and the clone he secretly enlists to replace himself (nicknamed Jack) in order to spare his family grief. When Ali first read the script, he had no idea how to tackle playing two identical men — a challenge that only made him want to try harder.

"As an actor, you get excited by scenarios that feel a little bit impossible," he explains. "You're like, 'How is this going to work?'"

A story about cloning and concepts like memory transfer and biomechanics may sound more like a high-tech epic than an intimate chamber drama. But Cleary and Ali (who also produced) wanted to focus less on the hardware and more on the emotional toll of Cameron's choice, exploring how it affects his identity and relationships. (Swan Song also marks a reunion for Ali and his Moonlight costar Naomie Harris, who plays Cameron's devoted wife, Poppy. "I was really excited to get to step on the stage and act with her again, with so much more time than we had in Moonlight, " Ali says. "I just had more time to learn from her and more time for her skillset and her approach to rub off on me.")

For Ali, his main goal was to find tiny variations between his two roles. "I wanted to be sure they felt distinct and that there were subtle differences that I hoped would collectively add up and read as two different characters," he says. "The main way in which that was done was in being very clear about who was in power." If Cameron is "more of a dog," Ali says, Jack is more catlike and "cautious." For sequences in which the two men talk to each other, the actor worked with a stand-in to rehearse every little glance and breath, performing each scene several times as Cameron and then again as Jack.

His biggest challenge came later in the shoot, during a moment in which Cameron and Jack actually come to physical blows. Apart from stunt doubling and some digital effects, the key, Ali says, was finding the chemistry within himself.

"It was emotional and challenging, but once I was finished, I could say that it was enjoyable," he says. "It felt like we accomplished something that I'd never done as an actor. It felt new."

A version of this story appears in the February issue of Entertainment Weekly, on newsstands Friday and available to order here. Don't forget to subscribe for more exclusive interviews and photos, only in EW.

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