The Garza family's Christmas vacation in Mexico is cut short by the
appearance of Pingo, one of the tzapame - Little People. The news is
grim - a rogue prince from an ancient undersea kingdom is seeking the
Shadow Stone, a device he will use to flood the world and wipe out
humanity. Now Carol and Johnny must join a group of merfolk and travel
into the deepest chasms of the Pacific Ocean to stop him and his
monstrous army with their savage magic.