In the ancient darkness of a mammoth cave, a cosmic secret lies buried

Working late in a deserted lab, a researcher named Gregor makes the discovery of the century. Within the dingy mottled surface of a stone named "moon rock 66095" lies unparalleled superconductive property—a power which, if harnessed correctly, could solve the world's energy problem once and for all. But when his supervisor tries to take credit for the breakthrough, Gregor murders him and hides the rock safely inside Kentucky's Labyrinth Cave. And his supervisor will not be the last man to die before Earth learns the secrets of moon rock 66095.

When NASA organizes a team to retrieve the magnificent rock, world-class cavers Tom and Whitney Burke are the natural choices to lead the expedition. But Whitney is still shaken from a terrible caving accident, and lets her husband and daughter go without her. When tragedy strikes the expedition, however, she must overcome her fears in order to rescue her family, plunging into a cave so deep that she may never see daylight again.