Grace, a harbor worker, discovers a mysterious bottle that connects her to Tristan, a captain fighting for survival centuries ago. She sends food and vital aid through the impossible link, while he returns priceless gifts and comes to see her as his miracle. Their distant devotion deepens as Grace provides medicine, arms, and a vessel from her world. But when the bottle breaks, she does not know Tristan has surrendered his life to the ocean for immortality, waiting five hundred years to find her.