Ripley and Zoe are survivors in a world burned to ashes by the spacefaring Dragoon Swarm. Together with an alien child they rescued, they fight tooth and claw to secure food and water, and evade the toxic fumes that begin to fill the sky.
There is a face behind the madness of the Invasion, and that face has a name: Doctor Tarr. Alone the doctor sits above the Earth; watching and waiting, at the behest of his Host, for the inevitable to come.