The last few days have been pretty hectic for young inventor Jean Ratlique. After rescuing Nadia and her pet lion King from the villainous Grandis, he's been chased, shot at, rescued by an American battleship, swept overboard, menaced by a sea monster, and rescued again, this time by a futuristic submarine named the Nautilus. Now he and Nadia are aloft once more, and headed for Africa. But the nearby deserted island isn't as deserted as it looks. And Grandis is still after Nadia's Blue Water gem. The adventure is just beginning!