The Nektons attempt to stop toxic fuel from a fallen satellite from polluting a marine sanctuary. But they encounter a mysterious new adversary, Alpheus Benthos, who has not only brought down the satellite himself, but wants to use the mapping data it contains to find Lemuria before them. When Ant and Fontaine track him down, it seems Alpheus believes Ant and he have a "shared destiny". He won't reveal what that is however. Will and Kaiko locate the satellite, but the casing around the power core cracks and leaks. It's going to explode, creating even more havoc, unless they can find a way to get rid of it. Ant has the crazy idea of shooting it back into space, but can they do it in time?