Jessica Chastain and Vanessa Redgrave have, according to The Hollywood Reporter, signed on to headline The Secret Scripture. Thaddeus O'Sullivan (Into the Storm) is attached to direct, adapting the novel by Sebastian Barry. Published in 2008, the book's detailed plot synopsis reads as follows:
In the beginning, Dr. William Grene’s interest in the almost impossibly old woman is merely professional, tinged perhaps with a hint of curiosity. Roseanne McNulty, one hundred years old, was one of the most beautiful girls in County Sligo, Ireland, in her youth. She has been confined in the Roscommon Regional Mental Hospital, where Dr. Grene is the senior psychiatrist, since the days of World War II. Now, in compliance with a change in government policy that has decreed the closing of the hospital, Dr. Grene is evaluating the facility’s patients to make dispassionate recommendations about which ones are mentally fit to resume life in society. As he interviews Roseanne to determine her mental state his neutrality evaporates. Reluctant to cooperate but curiously compassionate toward him, the ancient woman impresses him as “a formidable person,” and indeed she is. Cleverly, carefully, she keeps the doctor at bay, denying him access to the deepest secrets of her past.
All the while, however, Roseanne is at work on a personal narrative of the very facts she withholds from her doctor—the “secret scripture” of the novel’s title. Over a period of years, holding almost nothing back, she has patiently recorded the details of her preconfinement life, including her father’s ill-starred attempt to give comfort to a band of Irish rebels, a cataclysmic fire at a local orphanage, and the descent of her mother into derangement. Her narrative becomes a chronicle not only of her deep emotions, but also of a turbulent era in her nation’s history, from the upheavals of the Irish civil war to the German bombing of Belfast during World War II. It also speaks personally and poignantly of the struggles of Roseanne’s Protestant family to live a peaceful, unmolested life in the midst of religious prejudice. Slipping continually into her story is a dark and ominous specter: a Catholic priest named Father Gaunt who is committed to preserving the perceived purity of his flock and the values of his religion, even if it means destroying the lives and families of those who hold dissenting views. As Roseanne scribbles out her testament, Dr. Grene also prepares a journal, intended at first to contain his professional findings but soon expanding to contain his reflections on history, the human condition, and the failure of his relationship with his wife. Gradually, the two lonely diarists forge a bond, which, in the end, proves far closer than either could possibly have imagined.
Chastain and Redgrave will both play Roseanne at different ages.