Two years ago, a research group of eight people disappeared on the planet Midgard. Now a new expedition sends a rescuer after them, whose goal is to find survivors or identify the bodies of the dead, as well as destroy all traces of possible contact between the aborigines and earthlings. On Midgard there is a local humanoid civilization frozen in the early Middle Ages and somewhat reminiscent of Scandinavia in the Viking Age. Here any electronics fails, any advanced technology breaks down, but the rescuer, or as the locals call him, the Night Wanderer, is changed at the biological level, he is faster and stronger than any resident of Midgard. But neither earthlings nor the Wanderer himself yet know that the similarity of this world with the Earth is deceptive, that there are real monsters here, and the rescuer, and at the same time the inhabitants of the planet, will have to face true horror and madness that cannot be rationally explained.