Chen Haiyang, a heavily indebted fisherman, rescues Zhuzhu, a mermaid who accidentally fell into the water, while going out to sea on a stormy night. Zhuzhu understands the language of the sea's creatures, and with her help, Chen Haiyang harvests precious catches, bringing a turning point to his life. Afterward, the two together explore reef secret paths and shipwreck ruins, and also discover a special deep-sea spring. Chen Haiyang uses this to build an ecological fish farm, and his high-quality seafood is widely recognized, yet he encounters suppression from local merchants. Relying on the help of Zhuzhu and the marine creatures, the family firmly guards their original intent, writing a story of a desperate comeback and gentle companionship between humans and the ocean.