After tragedy strikes the Corbin family, David Corbin finds himself struggling to stay sane in a world that seems to be falling apart. His only wish is to live a peaceful life with his longtime love, Carrie Green, and discontinue his acts as the Hero of Anaisha. But as Legion- an alien species bent on world destruction - reveals more of itself through not only its invasion, but the symbiote that Carrie has vying for control of her body, David realizes that not only is his life in danger, but reality itself. Tears are forming between worlds, and the very fabric of time and space is in jeopardy. David will have to sacrifice his personal ambitions, his pride, and even his relationships in order to find an ancient codex that could be the key to stopping the chaos.

In an attempt to understand her Legion symbiote, Carrie Green retreats within herself in an attempt to communicate with Viranda DelaCourte, an entity of Legion that has sought to excommunicate herself from Legion as a whole. But Viranda's goals aren't just to break off from Legion. She also wants to help Carrie find the keys to a prison holding Legion's prisoners from all the worlds it has destroyed.

As the world begins to unravel around them, both David and Carrie find themselves at the crossroads of multiple dimensions, with not only their own lives at stake, but the fate of reality itself.