Mark Ruffalo will be pulling double-duty as a pair of identical twins in the upcoming HBO limited series I Know This Much Is True, premiering in April. The network’s official Twitter account just shared the first image of Ruffalo in character as Dominick and Thomas Birdsey.

Based on the novel of the same name by Wally Lamb, the series follows the twin brothers “in a family saga that follows their parallel lives in an epic story of betrayal, sacrifice and forgiveness. The series shows Dominick and Thomas at different stages in their lives, beginning in their present with both brothers approaching middle-age, filled in with Dominick’s flashbacks to their young adulthood.”

Collider had the chance to speak with Ruffalo recently about his film Dark Waters, and the actor offered some insight into his dual role in I Know This Much Is True.

“I play two characters. One of the identical brothers, one of them’s schizophrenic. We stopped shooting for six weeks so I could put on 30 pounds and totally change my look and character for the schizophrenic brother. And he’s [director Derek Cianfrance] doing some really bold stuff on this thing. And I don’t want to get ahead of it too much, but I’m really proud of what we were able to do while we were shooting it.”

Ruffalo also shared some details on how challenging the “brutally tough shoot” was, due to Cianfrance’s habit of filming very long takes. “My first day of work was a 23 page scene,” the actor said. “We spent the whole day shooting that scene over and over again from beginning to end. He would give us a note, maybe on one section of it, but we’d start at the beginning and shoot the whole thing. And it was a 25 minute scene. And that was our first day shooting. That’s how we broke everybody in… It’s very free emotionally. He creates a space where he wants you to fuck up. He wants you to push the boundaries. You always feel like you’re just kind of tripping over yourself. You’re never quite on your feet. You’re not flat on your feet, you’re always just a little bit out of control, which gives it that immediacy.”

Ruffalo is an electrifying performer with a career of amazing performances under his belt, and it sounds like he’s at the top of his game in this series. Check out the full image below, and click here to read our full interview with the actor. I Know This Much Is True begins its six-episode run in April on HBO.

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