As Autons swarm across the planet, the human race faces its darkest hour. Simon Devlin has helped his alien masters gain a global foothold and their scheme is almost complete. As UNIT leads the fightback on every front, every continent, against an implacable army, Kate Stewart must look to the past for some clue to defeat the plastic menace. The Nestene Consciousness is growing in power. It has plans for the human race, and when it achieves its ultimate form, it will be unstoppable. Only UNIT stands between humanity and total extinction...