Moments before the world ends, Simon, a dissatisfied history professor, walks along the San Diego boardwalk with his young daughter, Esther. Judith, an ambitious college senior, jogs nearby, trying to relax before her first big interview.
Hundreds of miles away, the giant volcano sleeping under Yellowstone erupts for the first time in 640,000 years. Ash and death spread in all directions. When Simon and Judith see the destruction rolling their way, they flee on the nearest available escape vessel: a cruise ship called the Catalina.
Adrift at sea, the survivors are cut off from all communication as the earth changes forever. Tensions rise between the stranded passengers, the crew, and the increasingly volatile old captain. As storms and threats roll in, Simon and Judith must work together to keep the peace in this dangerous new world. Will they find a safe haven on the other side of the ocean?