Anton is dying.  Macallan must take desperate steps to save his life and decides to literally step into the unknown and descend down the Marianas Trench, the deepest point on Earth.  There, she discovers the entrance to Leviathan - the secret immortal city created over 1,000 years ago.  Inside she finally comes face-to-face with Evangeline and finally discovers what lies within the walls of Leviathan!