The earth of our distant future has become a strange and frightening place. Now, thousands of years later, two off-worlder humans, Anna and Joe, are sent back to the wild and unpopulated planet to try to begin human life all over again. But what they discover is a world far more confusing, far more powerful, than they'd ever imagined. Rats that seem to reason for themselves? Creatures that communicate in ancient human codes? What is going on?