Four humans from the Twentieth Century are hurled forward a billion years in time by a being from an alien galaxy. They have been brought to a dying Earth - to Carcasilla, Earth's last citadel - where the mutated remnants of humanity are making their final stand against the monstrous creations of a fading world. Thrust in the middle of this desperate struggle for survival, the last humans search for a way to break the deadlock in the Armageddon at the end of time...