In 15th-century Krakow, a young boy and his family arrive under cover of danger, carrying a secret hidden in plain sight. They have fled the burned ruins of their home in the Ukraine, pursued by those who will stop at nothing to take what they guard. As foreign invaders threaten the Polish kingdom, enemies gather within the city walls-and a centuries-old oath must be honored, even at the cost of a life.

Amid market stalls, university halls, and the towering spires of churches, the boy discovers a world unlike any he has known. He meets a reclusive scholar, an orphaned girl, and a host of strangers whose motives are not always clear. While his father struggles to protect what must not be lost, the boy must decide whom to trust, what to believe, and how to act when courage matters most.

Blending true Polish legend with historical detail, this Newbery Award-winning novel explores the weight of loyalty, the mystery of heritage, and the power of silent resistance. It paints a vivid portrait of medieval life while asking what it means to keep faith with the past-and what is worth risking for the future.