After the greatest catastrophe in history, a purple Beam that shoots into the sky appears in the place where Moscow once stood. With each day, it spreads farther, copying the same section of the Bitsa Forest from the south of the capital. The few who survive in the infected territories encounter creatures from Eastern European folklore and hallucinations that force them to relive tragic events from Russian history. A research institute sends expeditions into the forest to reach the epicenter and uncover the nature of the Beam. At the institute, a group of teenagers with resistance to hallucinations begins their studies. Soon, they confront the past—something that compels them to rethink the catastrophe.