At the end of the Warring States period, Wu Jiu, a prince of an enemy state held hostage, secretly falls in love with Princess An Ge. On the day her kingdom falls, An Ge leaps from the city wall to die for her country, but her obsession and a secret technique turn her into an immortal. Spanning a thousand years, the story unfolds in reverse chronological order. An Ge witnesses the fate of Wu Jiu in every lifetime, and her hatred gradually melts away through their repeated encounters. In his final lifetime, An Ge assumes the identity of Wei An Ge, director of a historical research institute, and recognizes Wu Jiu at first sight when he is reincarnated as a student. She leads his reincarnation, student Lu Wu Jiu, in excavating a suspected burial site containing the ceremonial garments of a Warring States prince. Throughout the long river of history, an ancient family has continued to track An Ge, seeking to obtain the secret of immortality.