After saving someone from the sea, Lin Chen develops an exceptional sensitivity to tidal flat traces and seawater changes. Relying on his beachcombing skills, he repeatedly harvests seafood, but faces jealousy, competition, and framed setups from Wang Qiang. When he risks his life to rescue a trapped tourist during a rising tide, his video goes viral; later, clearing traps leads him to a giant conch and an old sea map. During a crisis at the distant reefs, he saves Wang Qiang, turning enemies into friends. Exploring hidden reefs according to the map, they discover a school of large yellow croakers and the Yellow Croaker King. As the Yellow Croaker King swims toward the open sea, small text on the map leaves a cliffhanger for a sequel.