Mark Ruffalo Gives Two Performances of a Lifetime in HBO’s I Know This Much Is True

Dominick and Thomas Birdsey are as different as identical twins can be. Born six minutes apart on opposite sides of midnight on New Year’s Eve 1950, they began life at the end of one decade and the beginning of the next—with separate birthdays and, as students during the Vietnam War, divergent draft numbers. When we meet them in I Know This Much Is True, an emotional miniseries based on Wally Lamb’s 1998 best seller that premieres May 10 on HBO, the brothers (both played by Mark Ruffalo) are 40 years old, and the disparities between them couldn’t be clearer. Thomas, a paranoid schizophrenic, has just walked into a public library with a knife and sliced off his own hand.

Dominick appears to be the responsible twin. With their mother (Melissa Leo) dead of cancer, leaving behind only a gruff stepfather (John Procaccino) who hit the boys when they were kids, he has dutifully managed his brother’s affairs. But Thomas’ public self-mutilation—which he says is an act of protest against the increasingly inevitable Gulf War, attracting national media thirsty for a crackpot prophet—plunges Dominick’s life into crisis too. After officials move Thomas against his will from his group home to a harsh, militaristic institution, an altercation sets off a spiral of events that reveal how tenuous Dominick’s apparent stability actually was.

The story’s biblical symbolism reaches far beyond Thomas’ literal interpretation of Jesus’ exhortation: “And if thy right hand offend thee, cut it off.” Like Cain’s murder of Abel, This Much asks whether one brother is the other’s keeper. Dominick’s successes tend to come at his twin’s expense, as was the case with Jacob and Esau. Their mom’s lifelong refusal to divulge the identity of their birth dad creates lingering questions about the sins of fathers real and imaginary, biological and adoptive, historical and expectant.

This excess of subtext comes straight out of Lamb’s 901-page tome, as does the ceaseless torrent of misfortune that threatens to drown the Birdseys. (Comfort TV this is not.) Though writer-director Derek Cianfrance smartly dilutes the melodrama with the same blunt realism that made his 2010 film Blue Valentine a gut punch, he doesn’t entirely succeed at bringing the narrative down to earth. And his unadorned approach doesn’t always work with subplots—including flashbacks to the life of the brothers’ Italian immigrant grandfather—that could’ve used more flair.

It’s Ruffalo who rescues the show from mediocrity, counteracting heavy-handed twists and on-the-nose lines (“You’re his mirror self,” Thomas’ psychologist, played by a well-cast Archie Panjabi, informs Dominick). And while A-list actors’ portrayals of mentally ill characters reliably attract awards attention, it is as Dominick that Ruffalo does some of his best work. Commanding as it is, his performance is also generous. It brings out the best in scene partners from the great Kathryn Hahn (as his ex) to Rosie O’Donnell, whose empathetic turn as Thomas’ social worker honors a tough, often thankless profession.

Righteous anger and raw vulnerability have long defined Ruffalo’s most memorable characters. Sometimes that intensity can overpower a movie, Incredible Hulk–style, yet it finds a perfect outlet in Dominick, a good but broken man who’s incapable of acknowledging the extent of his damage. After absorbing the pain of a failed marriage, a lost career and multiple deaths, it is Thomas’ ordeal that finally puts him in a position to get the support he so desperately needs. In the end, the Birdseys may not be as different as they look.