"Mephisto" is a symbiotic alien creature brought to Earth about 65 million years ago by a meteorite. It has grown since then from a small spawn to a net of interconnected, specialized grubs, reaching from Australia to the North Pole through both Americas. Now in the year 2050, the war on the surface above is blazing and furious like it was never before. Mephisto, slow as it is, has noticed that something on the surface wants to harm it and decides to participate in the war to defend itself.