Geologist and adventurer Philip Mercer is visiting Abe Jacobs, an old friend who's working far down in Minnesota's Leister Deep Mine. Abe is leading a research team to the deepest section of the mine for a ground-breaking study on climate change. But as Mercer approaches, he is stunned to hear automatic gunfire in the massive underground chambers. By the time he finds his way to them, Abe and the entire research team have been brutally attacked.

Mercer immediately retraces Jacobs's tracks, searching for clues to the secret project on which the distinguished scientist was working. Staying one step ahead of a highly trained team of assassins, Mercer follows a trail that leads from a harrowing close call in the Midwest to a nail-biting showdown in the mountains of Afghanistan. At stake is an extraordinary scientific discovery that could irrevocably alter the planet, centred on a cache of rare crystals called lightning stones - rumoured to have been aboard Amelia Earhart's plane when it vanished in 1937.