The latest pulse-pounding thriller from New York Times bestsellers Preston & Child.

In Colorado near the Cheyenne Mountains, a team of topflight engineers venture on an ambitious cross country ski trip, using their newly invented outdoor equipment. The strapping group of young people are having the adventure of their lives - skiing, laughing, playing in the snow, and mugging for the camera. But when the gang was expected to arrive back from their trip - no one ever returned.

Nora's excavation skills and Corrie's investigative talents are put to the test as they try to uncover what happened to the promising skiers on this cold and isolating mountain. But as more speculations and theories come to light, they fear this may be the hardest case to crack yet.