The Hardys' Christmas in paradise, Hawaii-style, could turn out to be one big wipeout. Checking out the world-famous dolphin research center at Nai'a Bay, the boys discover that one of the dolphins has suffered a suspicious injury, and that one of the researchers has vanished without a trace. Frank and Joe are convinced that the disappearance is linked to the notorious Hawaii Heist, a cache of hot jewels that was lost at sea in a plane crash. The Hardys are headed for treacherous waters -- stirring up trouble and swimming with the sharks!