In the distant past, Mesozoic creatures ruled the Great Ocean. Nelarr, a resident of the underwater kingdom of LeMaria, discovers that he can no longer breathe underwater, but needs oxygen from air to survive. Branded a freak of nature, he is banished from the kingdom and labeled an Outkast. It is when breaking the surface that he sees how far the horizon extends. Might there be some unknown place where he may not only survive, but build a new life–a place he can call . . . home. On his journey, he meets another nomad, a giant sea turtle named Mariner. Together, they must battle monsters and other Lemarians who want him dead.