Mark Ruffalo to play twins in HBO limited-series I Know This Much Is True

Dominick Birdsey's entire life has been compromised and constricted by anger and fear, by the paranoid schizophrenic twin brother he both deeply loves and resents, and by the past they shared with their adoptive father, Ray, a spit-and-polish ex-Navy man (the five-foot-six-inch sleeping giant who snoozed upstairs weekdays in the spare room and built submarines at night), and their long-suffering mother, Concettina, a timid woman with a harelip that made her shy and self-conscious: She holds a loose fist to her face to cover her defective mouth–her perpetual apology to the world for a birth defect over which she'd had no control.

Born in the waning moments of 1949 and the opening minutes of 1950, the twins are physical mirror images who grow into separate yet connected entities: the seemingly strong and protective yet fearful Dominick, his mother's watchful "monkey"; and the seemingly weak and sweet yet noble Thomas, his mother's gentle "bunny." From childhood, Dominick fights for both separation and wholeness–and ultimately self-protection–in a house of fear dominated by Ray, a bully who abuses his power over these stepsons whose biological father is a mystery. I was still afraid of his anger but saw how he punished weakness–pounced on it. Out of self-preservation I hid my fear, Dominick confesses. As for Thomas, he just never knew how to play defense. He just didn't get it.

But Dominick's talent for survival comes at an enormous cost, including the breakup of his marriage to the warm, beautiful Dessa, whom he still loves. And it will be put to the ultimate test when Thomas, a Bible-spouting zealot, commits an unthinkable act that threatens the tenuous balance of both his and Dominick's lives. To save himself, Dominick must confront not only the pain of his past but the dark secrets he has locked deep within himself, and the sins of his ancestors–a quest that will lead him beyond the confines of his blue-collar New England town to the volcanic foothills of Sicily 's Mount Etna, where his ambitious and vengefully proud grandfather and a namesake Domenico Tempesta, the sostegno del famiglia, was born. Each of the stories Ma told us about Papa reinforced the message that he was the boss, that he ruled the roost, that what he said went.

Mark Ruffalo will next be seen reprising his role of Bruce Banner for AVENGERS 4 on May 3, 2019.