Alex Cave, a geophysics instructor from Montana, receives an urgent message about an unusual geologic event in Iceland. When he arrives, he sees two video recordings. The first is of large globules of glowing magma rising from a glacier. The second video, taken in the exact same place several days later, shows a deep tunnel below the ice. He is asked to investigate the strange phenomenon, and what he discovers at the bottom is an alien device more powerful than a nuclear weapon. Before Alex can retrieve it, the device is stolen and activated, but it cannot be turned off. It begins dragging satellites from orbit and threatens to bring down the International Space Station. When it begins changing the orbit of the moon, Alex and his friends begin a desperate race to find the device and shut it down before the tidal effect rips the planet apart.