Another massive 10.5 quake tears apart the West Coast, threatening to turn the American landscape into a hellish wasteland. Seismologist Samantha Hill sees an even greater threat: an ever-widening fault line that's heading straight for the country's two largest nuclear reactors. If a meltdown occurs, millions will die. Samantha and the American president agree only one man can help them-the scientist who predicted this terrifying natural disaster years before-Samantha's own father, Dr. Earl Hill, now counted as a possible casualty of a massive Las Vegas quake. Together with a crack rescue team including Brad and Will, Samantha must find her father and stop the fault from slicing uncontrollably toward millions of people and the ultimate nuclear apocalypse.