In 1959, after a group of nine student hikers are found dead in the Ural Mountains, KGB Major Oleg Kostin is sent to investigate. During the autopsy, Oleg has a flashback of a disturbing memory from WWII.
Nine days before the group's death, the hikers pass through a small village where they learn about the region's Indigenous Mansi people, who have named the mountain they're headed toward the Dead Mountain.
The group reaches the pass and sets up camp. As the night progresses, the conditions worsen and their struggle becomes unthinkable. Each harrowing detail fills in the puzzle pieces of what really happened to the Dyatlov hikers.