Dr. Steven Sorenson plans to tap the geothermal energy of the Earth's interior by means of a thermonuclear device detonated deep within the Earth. This experiment causes a crack to form and grow within the Earth's crust, which threatens to split the earth in two if it is not stopped in time.

When an asteroid hits the Earth leading to underwater volcanic eruptions, the inhabitants of a small riverside town start to flee inland. Before she leaves, Nian decides to say goodbye to her childhood friend. Her memories of the town start to become clearer and clearer in her mind on this journey.

12,000 feet down, life is erupting. Alvin, a deep-sea mechanized probe, makes a voyage some 12,000 feet underwater to explore the Azores, a constantly-erupting volcanic rift between Europe and North America.

With the help of diver and biologist Laurent Ballesta, a scientific expedition explores three sunken Italian volcanic sites in the Mediterranean.