The Witch's Ring

1927. A staff member of a special group of the OGPU Special Department, Vadim Arsenyev, returns to Moscow after an official trip, but not far from Perm he is taken off the train and delivered to the local criminal investigation sub-department. It turns out that in the area, a mysterious murder has been committed using an unknown weapon. In addition, stubborn rumors circulate through nearby settlements about flying devices of a strange design supposedly appearing in the sky and people in silvery coveralls. The police believe these stories are inventions, but the murder case gains serious attention, so Vadim— as a specialist in anomalous phenomena—is asked to join the search for the mysterious criminals…