In the stunning follow-up to Exo, Earth’s century of peace as a colony of an alien race has been shattered. As the government navigates peace talks with the human terrorist group Sapience, Donovan Reyes tries to put his life back together and return to his duty as a member of the security forces. But a new order comes from the home planet: withdraw. Earth has proven too costly and unstable to maintain as a colony, so the aliens, along with a small selection of humans, begin to make plans to leave. As word of the withdrawal spreads through the galaxy, Earth suddenly becomes vulnerable to a takeover from other alien races. Invaders who do not seek to live in harmony with humans, but to ravage and destroy the planet for its resources..As a galactic invasion threatens, Donovan realizes that Sapience holds the key that could stop the pending war. Yet in order to save Earth, all species will have to work together, and Donovan might just have to make the ultimate sacrifice to convince them. But can one person save an entire planet from total extinction?