1923 Part of the territory of the former Russian Empire went to Poland, including the Osowiec fortress destroyed during the First World War, famous for the “attack of the dead.” The new owners clear away the rubble and discover a living man in the dungeon, who spent several years in a stone bag! Vadim Arsenyev is dressed in the uniform of a serviceman in the tsarist army, he does not remember his past at all, but has acquired amazing qualities: the ability to see in the dark and lightning-fast reactions... A sensational story ends up in the newspapers, and Vadim is handed over to the Soviet side. As an interesting patient whose abilities are useful to study, Arsenyev first ends up in the Brain Institute, and then in a special department of the GPU, formed from people with unique talents. As part of a small detachment, Vadim goes to the Far North to investigate a mysterious and suspicious case...