Halfway through Sebastian Barry’s powerful new novel, an elderly psychiatrist reflects that ‘we are never old to ourselves. That is because at close of day the ship we sail in is the soul, not the body.’ The Secret Scripture traces the long, perilous voyages of two souls: sixty-something Dr Grene, and his favourite charge, Roseanne McNulty, nearly a hundred years old and sequestered since the Second World War in psychiatric institutions. Now, in a room high in an old Sligo asylum, she’s beavering away at her memoirs, her only visitors the kindly, grief-stricken shrink and a trusty inmate who wheezes up the staircase each day to clean the room. Despite her age, Roseanne’s recall is vivid; her voice that of the young woman who was locked away before Grene was born. But her sanctuary is due for demolition, the inmates to be relocated to a bright new establishment or let loose into the community. It’s Dr Grene’s job to decide the fate of Roseanne, but she’s a tricky case, not least because her notes are incomplete and nobody seems to know why she was locked up in the first place, incarceration having been enforced as often for social as psychiatric reasons.