“Paternity”, wrote James Joyce, “is a legal fiction”. For Sally, the heroine of Grace and Truth, paternity is indeed the forbidden fact which holds the key to her identity. Sally grew up without a father, her unhappy mother acting out the impossible lie that no such man existed. Now a successful actress, she has made her name by cultivating the pretence that she first knew as a child. But when her husband leaves her, Sally decides that her gift for pretending has kept her from knowing how to love. She needs to find out who she really is before she can understand anyone else. In Jennifer Johnston’s hands, this premiss proves less trite than it might. Sally sets out to escape the secrets and lies of her upbringing by discovering the truth about her father, and the tale of troubled self-discovery that unfolds does not pander to expectations.

She begins her quest by visiting her grandfather, an austere ex-bishop, whom she barely knows. After several terse interviews the old man thaws towards her. He gives her a private memoir to read, all fifty pages of which are spliced into the body of the novel. It would spoil the story to elaborate too far on the bishop’s revelations. Suffice to say that his tale would not be out of place in Ovid. It is the truth, and though it may shock, it also brings with it a healing power, the redemptive “grace” of the title. After years of worry and bitterness, Sally is able to forgive the lies of her family, and reconcile herself with love.

Johnston has written a powerful book. She sensitively examines those themes - of paternity, of reality - that have always been the domain of literature. Sally, we learn, has just completed an acclaimed London run of a production of The Playboy of the Western World by J. M. Synge, a drama about the complex bond between parent and child. She and her grandfather recite together a scene from The Tempest which turns on a father’s relationship with his daughter, and illustrates the dangers of a life lived as an “insubstantial pageant”.

Johnston’s literary references never complicate her writing, but illuminate it, creating a rich and perceptive blend of poetry and experience. The narrative of Grace and Tr uth, however, is sometimes awkward. it is hard to glean a sense of personality from Sally’s stylized first-person narrative, which is full of half-line paragraphs, ellipses and onomatopoeia: “squeak”, “phew”. Although these do convey the fragmented tumble of her thought-process, they are too self-conscious, a literary device rather than a credible idiom. And parts of the novel fail to ring true. Johnston does not seem quite at ease writing about twenty-first-century Ireland; references to the euro, for example, and Nicole Kidman feel forced. In contrast, the bishop’s memoir is an accomplished piece of story-telling. Johnston is at home among the morals and tragedies of an earlier generation, and the bishop commands more of our sympathy than Sally does, largely because he is better written.

Perhaps this is an example of style mirroring content. History, after all, is a nightmare from which Sally only awakens at the end of her tale, when she finally knows where she comes from. Throughout Grace and Truth Jennifer Johnston remains preoccupied by the hold that the past has over the present. “When Sally raids her grandfather’s memory to find out her identity, she shows that we are more than the sum of our experiences. We are made from the facts of history, and only when we have made peace with that history can we learn to be ourselves.