In the winter of 1926, the silent peaks of Mount Everest conceal more than snow and rock. When a small team of explorers—an exiled Austrian soldier haunted by war, a daring Sherpa guide with secrets of his own, and an ambitious American photographer—set out to climb the mountain, they expect only hunger, cold, and the fight for survival.

But Lady Hargrave, a wealthy patron, has given them a different mission: to find her missing nephew, last seen high on Everest's unforgiving slopes. Driven by loyalty and desperation, the team ascends into a world where avalanches roar like cannons and shadows move where no living thing should be.

Night after night, something follows them. Something that knows the mountain better than they do. As they climb higher into thin air and frozen silence, they begin to suspect the truth about the missing men—and the terrifying force that waits for them above 28,000 feet.