In a pioneer camp near Moscow, an outbreak of an unfamiliar disease flares up. Almost immediately, inexplicable events begin to occur, and Kolyka Pozharskiy becomes a witness—he is taken on as an assistant to an operational police unit. In front of his eyes, the camp’s new director, Arkadiy Mantsev, suddenly dies. A few days later, the physical education instructor—also the night watchman—dies. And when Pozharskiy, at night, finds himself in the medical outpost, he encounters an armed stranger who immobilizes him with a poisonous substance. As he loses consciousness, Kolyka understands: this is the very inhuman creature that keeps the entire staff in fear, and it won’t stop at anything…