Driven to find the sunken mythical kingdom, a young adventurer named Milo discovers an ancient journal with clues to its hidden location. Along with a skilled yet quirky group of explorers led by the confident commander Rourke, Milo boards the Ulysses, an amazing state-of-the-art submarine, for a risky expedition to the bottom of the sea. There, they discover a lost continent of supreme technology, mystical power and priceless riches. But when a surprise takeover plot surfaces, Milo's mission switches from finding Atlantis... to saving it.