Book III of Man From Atlantis. The dread moment had arrived - a space probe had carried back alien spores. Active, intelligent, indestructible, they were unlike anything science had seen before. Invading human bodies, creating havoc and madness, Mark Harris knew he would serve their will. The alternative was too overwhelming to consider - not just for him but for all mankind. The spores had come; the Earth was their hostage. There was only one way to send them back, but time was running out...