The stories are the stuff of legend, and they are all true. In 1811 and 1812, three earthquakes measuring 8 on the Richter scale ruptured an area spanning twenty-four states and a third of the land mass of the United States. Lakes formed in Tennessee, church bells rang in Boston, and the mighty Mississippi ran backward.But today it is all a distant memory. Until the underground force reawakens. Kentucky farmers say animals are acting strange: cows butt each other with unheard-of aggression and a few hundred rats race across a road in broad daylight. In the Ozark Mountains, leaking subterranean gases flash bursts of red and green across the midnight sky. Suddenly the earth beneath a sleepy Tennessee town "liquefies" in a fountain of mud and foul-smelling water.A man and a woman, both seismologists, find themselves in a race against the clock to convince the world that their daring mission is the only way to stop the last monstrous earthquake to come. History is about to repeat itself. It's Mother Nature calling.