The Urals, the great mountain range separating Europe from Asia, has many charms for those who wish to practice mountaineering. There is no lack of mountains and passes to challenge the courage of hikers who dare to face it. In winter, the harshness of its climate makes it an inhospitable region, almost a desert. There are however many candidates for the ascent. But one day in February 1959, a group of hikers died there in circumstances so tragic that they suggest that strange activities were taking place...

July 3rd, 1947. The summer sky over New Mexico in the southwestern United States is stormy. Flashes of lightning streak through the night and thunder rumbles. In the early morning, Mac Brazel discovers metal debris strewn on the ground of his ranch in Corona. Unable to identify them nor to understand their origin, he shows them to his neighbors, the Proctors. They can't identify them either. By mutual agreement, they decide to show them to Sheriff George Wilcox. Just as intrigued, the latter alerts the Roswell military base, which sends two soldiers to examine them : Major Jesse Marcel and Captain Sheridan Cavitt. On July 7th, 1947, they themselves recover more debris and bring it back to the base.

Flying over the high plateaus of Peru, one can discover an archaeological treasure traced on the ground and classified as a World Heritage Site by UNESCO : the Nazca geoglyphs. These gigantic drawings represent animals, geometric or humanoid figures. But what do they mean ? Why did the Nazcas draw these extraordinary designs, some of them over a half of mile high ? How did they do it since they had no way to get up in the air to get a bird's eye view ? When the Nazcas were a prosperous people, why did they abandon their plateaus, leaving behind their drawings and burying their pyramids ? Why does a civilization die out ?