Off the coast of Bermuda and more than a quarter mile below the ocean's surface rests the American Department of Preternatural Activities (DPA) Poseidon Base. A transparent dome enclosing ruins that are over twelve thousand years old, guarding the secrets of humankind's past. For a decade, Poseidon Base sat peacefully and hidden from the world until a sneak attack from the DPA's adversary. The Thule catalyzes the ancient technology under the sea, and Poseidon Base disappears from our Earth. Seconds later, Posideon Base's personnel and their Thule attackers find themselves on a parallel Earth with no idea how to find their way home.