Qin Siyuan, an immortal shopkeeper of "Wu Wang Zhai," spends her days guiding souls to the afterlife, lighting lanterns to fulfill their last wishes. Bound by her past sins, she cannot end her own life. When Shen Zheng stumbles into her shop, an unusual event reveals that he is the key to ending her eternal wait. However, Qin Siyuan learns that Shen Zheng's life will end before he turns twenty, and she decides to extend his life, hoping to fulfill both their destinies.