Marion and Shiva Stone are twin brothers born of a secret union between an Indian nun and a British surgeon at a mission hospital in Addis Ababa. Orphaned by their mother's death in childbirth and their father's disappearance, they are bound together by a preternatural connection and a shared fascination with medicine. Marion flees his homeland fresh out of medical school when he and his brother fall in love with the same woman. He goes to work in an underfunded New York hospital until his past catches up with him, nearly destroying him, and he must trust his life to his father and brother.