Aspen Matthews was born of two worlds—The OCEAN and LAND. Now, deeper within the confines of The Earth—a new threat has risen, one that will reclaim the eco-system for those of much more powerful descent. The human world has tenuously learned to co-exist with the underwater species known as The Blue. The powerful Elite Blue Aspen Matthews has returned to her life''s work—that of a marine biologist. Yet, not all creatures from below are seeking peace, and when an unimaginable force from the deep confines of The Earth''s core makes their presence felt in a catastrophic way, Aspen and the entire Fathom Universe must unite in order to not only save themselves—but the entire planet!