Against the backdrop of the generation ship Seed leaving for Tau Ceti, a quiet battle unfolds between Entropy and Consciousness. Entropy is an unseen character, only visible through his all-powerful equations. Against him stands SC8, a boy growing up on a secret asteroid base. Together with his prophet, they plot how to uplift humanity to a high enough level of consciousness to win the war. The humans will die off either way. Retreat to Sol encompasses quantum mechanics, philosophy, and cosmology as the goal of an Earthly hive mind is reached, and then surpassed. Entropy leverages uncertainty and creates a black hole in the sun to destroy the humans, but is thwarted by SC8’s uplifting them to immortal Gaeans. Entropy adapts and increases the cosmological constant in order to destroy all of existence. The Gaeans are forced to explore the furthest reaches of the universe searching for a solution. But can they find it in time