Just after a typhoon, Chen Fu's old injuries flare up again. To raise money for his adoptive father's treatment, Chen Chao risks entering the treacherous Rocky Bay to forage for seafood. After finally catching a giant octopus, his partner Zhao Gang steals the catch and takes away his safety rope, leaving him trapped as the tide rises. Chen Chao escapes across the waves and exposes Zhao Gang in front of everyone, but without evidence, he is met with suspicion instead. Su Qing, the daughter of a seafood buyer, offers him a three-round trial supply challenge. Using his ability to read the tides and locate hidden holes, Chen Chao repeatedly discovers new seafood hotspots among reefs, mudflats, and tidal channels. But Zhao Gang keeps laying traps involving stolen fishing spots, swapped catches, and false information. Then a sudden massive tide pushes everyone to the brink of life and death.