Set in 1914, young linguist orphan named Milo Thatch(Michael J. Fox) buries himself in books trying to unlock the secret to the destruction of Atlantis. Althouth his theories are ridiculed by his colleagues he is persistent in his dreams of one day discovering the lost isle. His dreams are realized when he is given a spot in an expedition, financed by a friend of his grandfather, to go in search of Atlantis following Milo's guide: The Shepard's Journal. But the Guardians of Atlantis await the explorers putting them in danger at every turn. And the deadly truth about Atlantis's demise puts Milo, the royal family, and all of Atlantis in mortal jeopardy.