With the Dark Druids after him and a magical war brewing, thirteen-year-old Jake Everton must lie low for a while, so his Elder witch aunt takes him and the gang on a long beach holiday, out of harm's way. But sure enough, Jake plunges into trouble once again when he meets a feisty royal mermaid on the run. Princess Sapphira, daughter of King Nereus, recently ventured into the deep and stumbled upon a powerful artifact from ancient Atlantis. But the mysterious orb holds deadlier secrets than she ever suspected, and now every power-mad tyrant in the Seven Seas wants it--especially the dread, undead pirate king, Captain Davy Jones. When the legendary Lord of the Locker invades her father's kingdom and takes her little sister hostage, demanding the orb in exchange, Sapphira blames herself for the catastrophe and means to hand it over. But Jake finds out that if Jones gets the orb, he'll use its power to drown the world in a second Noah's Flood! Now it's up to the aspiring young Lightrider and his friends to help the mermaid rescue her little sister and save the world from the same watery doom that drowned Atlantis--if Jake and the headstrong princess don't strangle each other first!