The Secret Scripture by Sebastian Barry was named “Novel of the Year” for 2008 at the Irish Book Awards and was short-listed for the Man Booker Prize for Fiction. The novel tells the story of Roseanne Clear McNulty, a patient at Roscommon Regional Medical Hospital. Dr. William Grene has been her psychiatrist for 24 years. Roseanne is near 100 years old but doesn’t know her true age. She was first a patient in Sligo Mental Hospital, nicknamed Leitrim Hotel because of its large population of Sligo citizens. Roseanne’s in-laws, the McNultys, who were employees at the hospital, worked with Father Aloysius Mary Gaunt, a stern local priest, to have her committed there. While growing up, Roseanne was close to her father, Joe Clear, a Presbyterian who worked as a superintendent at a Catholic cemetery in Sligo. Joe Clear entertained Roseanne with stories, many of them about his years in the British Merchant Marine.

While Roseanne writes her personal history, or “testimony,” Dr. Grene writes his observations of her in his commonplace book. The narrative shifts between these two characters, whose seemingly disparate lives converge as the novel progresses. Dr. Grene is eager to question Roseanne to learn more about her, but he doesn’t want to offend her because of his fondness for her. John Kane, the custodian at the asylum, also looks after Roseanne.

In her youth, Roseanne trailed along with her father, Joe, when he served as superintendent at Sligo’s Catholic cemetery. Father Gaunt later fired him from the job for helping the anti-treaty rebel, John Lavelle, bury his murdered brother, Willie Lavelle. Father Gaunt gives Joe Clear a job as a rat-catcher instead. One day, while working at an orphanage, a paraffin-soaked rat escaped from Joe’s grip before he could throw it into a bonfire with the other rodents. The rat later caused a fire which burned down the orphanage. Meanwhile, Roseanne’s mother, Cissy Clear, descended further into madness and, in Roseanne’s memory, her father hung himself. Dr. Grene, however, one day reads Father Gaunt’s deposition, which claims that the Irish Republican Army (IRA) murdered Joe, in revenge for his previous activities with the Royal Irish Constabulary (RIC).

Later, Father Gaunt visited Roseanne to convince her to convert to Catholicism and to marry the much older Joe Brady. She refused, and Father Gaunt resented her for her perceived stubbornness. While learning these aspects of Roseanne’s story, Dr. Grene thinks about his estrangement from his own wife, Bet, because of his affair with a colleague. Bet died as a result of her poor health. After telling Roseanne the news, she comforted him, which surprised Dr. Grene.

After Roseanne’s father died, she took a job at Café Cairo in Sligo, working as a server. While there, she met the jazz musician Thomas “Tom” Oliver McNulty, a member of a middle-class Catholic family. They fell in love and married, despite the disapproval of Tom’s strictly Catholic mother, Mrs. McNulty. During Roseanne’s marriage, John Lavelle reentered Roseanne’s life and asked to meet with her on Knocknarea. Against her better sense, Roseanne agreed, unable to resist her kinship with him. On their way downhill, they ran into Father Gaunt among a group of other clergymen. Father Gaunt used this event to convince Mrs. McNulty and Tom that Tom and Roseanne’s marriage should be annulled. Tom agreed, and Roseanne was thereafter condemned to live alone in a hut, ostracized from the Sligo community.

One day, Roseanne saw a soldier pass along her street, covered in ash. He strongly resembled her former brother-in-law, Jack McNulty, but he turned out to be Eneas McNulty—the “black sheep” of the McNulty family. Roseanne and Eneas bonded and ended up making love. The encounter resulted in pregnancy. Unable to get help from the McNultys, Roseanne gave birth alone on the beach and collapsed in exhaustion. When she awakened, she realized that her baby was gone. A pair of paramedics picked her up and took her to the hospital, where Father Gaunt arrived and told her that he knew of a place where she’d be safe—Sligo Mental Hospital, resulting in her spending the remainder of her life confined to asylums.

While Roseanne is writing her testimony, Dr. Grene is reading Father Gaunt’s deposition against her, which reveals what is likely the truth of Joe Clear’s death—not suicide, but murder—and makes a solid case for what Father Gaunt perceived as Roseanne’s nymphomania. With the help of his former colleague, Percy Quinn, Dr. Grene obtains records confirming Joe’s service in the RIC and learns that Roseanne’s mention of “Nazareth” refers to Nazareth House, an orphanage in England where her child ended up. In an ironic twist of fate, Dr. Grene learns that he is the child whom Roseanne lost at the beach on Strandhill. He rushes back to Ireland and visits Roseanne, whose health is steadily failing. He declares that she was wrongly accused and ought to be a free woman; she thanks him. Dr. Grene goes to John Kane’s quarters to question him because he’s learned that Kane arranged for Roseanne to be at Roscommon so that she could be close to her son. Shortly thereafter, Roscommon Hospital is demolished and Dr. Grene imagines that he sees Kane, in the form of an angel, rising from its ashes. Dr. Grene later drives to Sligo, to the beach where he was born and to the place where Roseanne’s hut existed. The hut is gone, but Roseanne’s old rose bush remains. Though untended, it retains some blooms.