Northern Morocco: Dr. Kate Warner cured a global pandemic, and she thought she could cure herself. She was wrong. And she was wrong about the scope of the Atlantis conspiracy. Humanity faces a new threat, an enemy beyond imagination. With her own time running out and the utter collapse of human civilization looming, a new hope arrives: a signal from a potential ally.

Arecibo Observatory: Mary Caldwell has spent her life waiting, watching the stars, looking for signs of intelligent life beyond our world. When that day comes, Mary finds herself in the middle of a struggle older than the human race, with far greater stakes. She must decide who to trust, because there's nowhere to hide.

Antarctica: In the wake of the Atlantis Plague, Dorian Sloane finds himself a puppet to Ares' mysterious agenda. As Dorian prepares to take control of the situation, Ares unleashes a cataclysm that changes everything. As the catastrophe circles the globe, Ares reveals the true nature of the threat to humanity, and Dorian agrees to one last mission: find and kill David Vale and Kate Warner. There will be no prisoners this time. The orders are seek and destroy, and Dorian has been promised that his own answers and salvation lie on the other side.

With Dorian in pursuit, Kate, David, and their team race through the ruins of the Atlantean ship left on Earth, across Atlantean science stations throughout the galaxy, and into the past of a mysterious culture whose secrets could save humanity in its darkest hour. With their own lives on the line and time slipping away, Kate, David and Dorian are put to the ultimate test.