London, 2024: When American expat Margo Reynolds is hired to source a book that’s more than one hundred and twenty years old, she thinks her greatest challenge is going to be that there’s only one copy in existence. However, it quickly becomes clear that her client isn’t the only person determined to procure the book at any cost. Thrust into a deadly quest, Margo teams up with an unlikely ally—the man she loved and lost—and is forced to confront the ghosts of her own past as the lingering feelings that simmer between them ignite. Havana, 1966: Pilar Castillo’s days are spent working as a librarian in Havana, her nights spent hoping for her husband’s freedom after his unjust imprisonment. But Pilar has a secret that could jeopardize her life. She’s fighting Fidel’s regime in her own way, and when she comes into possession of a book that was published more than sixty years earlier, she must decide how much she’s willing to risk to protect the literary works entrusted to her care. Boston, 1900: For Cuban teacher Eva Fuentes, traveling from Havana to Harvard to participate in the largest cultural exchange between Cuba and the United States is not only a chance to represent her country at a critical time in its bid for independence, but also an opportunity to work on the book she’s writing. When a moonlit encounter with an enigmatic stranger alters the course of Eva’s summer at Harvard, and as secrets, lies, and forbidden love rise to the surface, Eva’s life—and legacy—is irrevocably changed.