Imagine that an astronaut goes through a space-time warp, bringing him home after 250 million years have passed on Earth. Continents are unrecognizable and every trace of mankind has vanished. To envision what this spaceman would see, experts travel around the world rediscovering our past in order to make predictions about the future. Asteroid collisions, glaciations and sudden volcanism are what created our present world. What natural forces may be responsible for our demise?

Our theoretical spaceman blasts into the future to imagine what Earth will be like 250 million years from now. He'll search for signs of past human life, but with all our landmarks dissolved away his only hope is to find a fossilized city that has survived nature's powerful forces. Perhaps he can find New Orleans, which would have been buried under the Mississippi Delta. What will the evidence he finds reveal: further evolution, or the destruction of our species?