Molly and Neil Sloan awake to see golden rain falling. In their remote California mountain town, they learn from their television of enormous waterspouts and blizzards around the globe; then, the television ceases, as do all other forms of communication with the outside world. The Sloans are left, together with their neighbors, in the midst of a purple fog, disturbed by a threat they cannot identify or understand. Together they discover that the world is being prepared for beings other than themselves--beings with vast technological powers at their disposal, who will stop at nothing to hunt them down and kill them all.