Just after graduating from university, Xu Chuan faces the mysterious disappearance of his parents and is saddled with a million-yuan debt. The dilapidated reservoir his parents left behind becomes the target of Zhao, a creditor who intends to seize the land and develop it into a resort. At his most desperate moment, the Giant Creature Breeding System activates. With spiritual water transformations and berserk genetic potions, the reservoir begins producing enormous fish. Xu Chuan introduces a fishing fee of 10,000 yuan, with a 100,000-yuan prize for anyone who catches one. This attracts fishing influencers and enthusiasts from all over, who repeatedly snap their fishing rods and make the reservoir an overnight sensation. But Zhao refuses to give up. After an unsuccessful poisoning attempt, he conspires with the Fisheries Association, accusing Xu Chuan of introducing mutated invasive species and polluting the ecosystem. They intend to drain the reservoir and destroy everything he has built. Now, the colossal creatures lurking beneath the water are about to emerge and fight back.