After Penglai Island sank, Xiyin gave the mermaid pearl to Yan Lie to save him, but she herself sank into the sea and disappeared without a trace. The mermaids also disappeared from the world. Shen Mei, the favorite concubine of the dynasty, coveted the mermaid pearl in the mermaid's body and lured Yan Lie to go to Peach Blossom Island with her to find the mermaid. During the trip to Peach Blossom Island, Yan Lie unexpectedly met his old love again, but Xiyin had lost all her memories due to the catastrophe that year. At this time, Shen Mei was also brewing a conspiracy. Where will the two people in danger go...