Sabine, the youngest physician at the Royal Hospital, is executed for a prescription she never wrote. The crown prince she tried to save does not arrive. She wakes in the modern world restrained in a psychiatric van — stepsister Sloane locked her in Greyhaven and only released her for a brief family visit. To reclaim her freedom, Sabine enters a ninety-day contract marriage with Rafe Calder, a reclusive heir hiding a congenital heart condition. He needs a wife to unlock his trust; she needs legal standing to escape. Using silver-needle techniques from her past life, Sabine stabilizes him and recognizes in Rafe the face of her dying prince. As his buried memories surface, she discovers the Bellamy medical institute was built on her own centuries-old research. Sloane's schemes escalate from staged fires to forged documents, until she attacks Sabine at a gala. Rafe takes the blade and, falling, calls her by her historical name — proof he remembers the life where he arrived too late.
