For 500 years, Ji Shichuan has sought the spiritual pearl within Yun Xi, but it’s fused with her heart and requires her voluntary sacrifice for his survival. After rescuing her, he protects Yun Xi until the next blood moon, as her pearl grants her unique healing powers that attract danger. Unaware of his true intentions, Yun Xi's affection for him deepens over seven years, while Ji Shichuan wrestles with the choice between saving his life or hers.