 A million-year-old humanoid shark, frozen in a block of ice, is on display at Aqua World. But it seems to have come back to life. This strange event is made stranger by the theft of a maharajah s jewels. It s up to Scooby and the gang to solve this maritime mystery. . . . The mysterious Ironface, whose identity is hidden by a sinister-looking iron mask, kidnaps the city s officials and its two superheroes, Blue Falcon and Dynomutt the Dog Wonder. The motive: revenge. But for what? No one knows who this strange Ironface really is.