Exploring Tales of the Strange

A mysterious notebook left behind by my grandfather! It records a strange tale from the past! Fifty years ago, my grandfather went with his unit into a remote, uninhabited region of Tibet to explore an unknown civilization. He endured blizzards and devastating avalanches, and witnessed a group of Germans vanish... But why did his teammates betray him? Why did his comrades become headless walking corpses? Was it a lingering curse, or the inescapable end fate had in store?