Xiao Lan, a marine animal protection officer at an aquarium, transmigrates into the body of a foolish criminal slave sentenced to exile. Shen Qinghe takes him home, where he unexpectedly awakens a water-based supernatural ability. To overcome their struggle for survival, he uses his powers to catch fish and produce salt. Along the way, he forms deep bonds with Shen Qinghe and the people around her, earning the recognition of the entire village. He also turns the tables on Sun Gui, a fellow exiled criminal slave who sides with the Zhao family and constantly bullies the Shen family; Zhao Dehou, who murdered the Shen couple to seize their family fortune; and Zhao Yuanheng, who framed and caused the deaths of the entire Xiao family. Helping Shen Qinghe build her own family business, he leads independent households in establishing the Canghai Association. As their wealth steadily grows, they transform Whale Fall Bay into the Great Zhou Dynasty's foremost trading port.