In the Arsenyevsky Forest there is a pit - a depression of unknown origin, where time distortions occur, which in turn distort certain areas of space. A group of university students, wanting to celebrate the end of their studies, makes a foray from the dacha to Pit. As they are about to leave, driven by an incomprehensible anxiety, they encounter a giant praying mantis. The guys are destined to take refuge in a small abandoned farm with only one inhabitant, where there is no telephone or other means of communication. Only the one who sees a weak side in the behavior of the praying mantis can save the survivors.