Inga Karlson died in a fire in New York in the 1930s, leaving behind three things: a phenomenally successful first novel, the scorched fragments of a second book—and a literary mystery that has captivated generations of readers. Nearly fifty years later, Brisbane bookseller Caddie Walker is waiting in line to see a Karlson exhibition featuring the famous fragments when she meets a charismatic older woman. The woman quotes a phrase from the Karlson fragments that Caddie knows does not exist—and yet to Caddie, who knows Inga Karlson’s work like she knows her name, it feels genuine. Caddie is electrified. Jolted her from her sleepy, no-worries life in torpid 1980s Brisbane she is driven to investigate: to find the clues that will unlock the greatest literary mystery of the twentieth century.