Wally Lamb is the author of five New York Times bestselling novels: She’s Come Undone, I Know This Much Is True, The Hour I First Believed, Wishin’ and Hopin’, and We Are Water. Philip Ettinger’s dual role in “I Know This Much Is True” hit very close to home. Starring Mark Ruffalo and written/directed by Derek Cianfrance, it's based on Wally Lamb's 1998 novel of … I Know This Much Is True is an emotionally harrowing tale, but Ruffalo’s performance is so remarkable that you’ll find hope in the relationship between the Birdsey brothers. I Know This Much Is True is HBO's latest prestige miniseries. WARNING: The following contains spoilers for I Know This Much Is True, airing Sundays on HBO.. One of the biggest secrets in HBO's I Know This Much Is True has been the identity of the father of the Birdsey twins, Dominick and Thomas (Mark Ruffalo). The 'I Know This Much Is True' Book is a Big Deal; The Complete 'I Know This Much Is True' Soundtrack; Read the 'I Know This Much Is True' Bible … HBO’s I Know This Much is True is a gripping adaptation of Wally Lamb’s bestselling novel. Mark Ruffalo as Dominick Birdsey, who is the twin brother to … I Know This Much is true is a tough but very enjoyable series to watch. The HBO mini-series “I Know This Much Is True” is a tale of twins who set a high bar for tragedy. It haunted them all their lives, but less so for Thomas as he was in and out of mental institutions for his paranoid schizophrenia. His first two works of fiction, She’s Come Undone and I Know This Much Is True, were both #1 New York Times bestsellers and selections of Oprah’s Book Club. Mark Ruffalo's performance is excellent and he deserves a lot of credit for it. Watch I Know This Much Is True Streaming Online | Hulu (Free Trial) TVMA • Drama • TV Series • 2020 A family saga that follows the parallel lives of identical twin brothers in an epic s... more Add HBO Max™ to any Hulu plan for an additional $14.99/month. I Know This Much Is True is based on Wally Lamb’s bestselling novel of the same title which was published in 1998. I Know This Much Is True is the second novel by Wally Lamb, published in 1998.It was featured in Oprah's Book Club for June 1998.