Russia, end of XIX century. In an abandoned estate near St. Petersburg is a series of mysterious murders of villagers. Arrived at the scene of the crime agent of the provincial investigation Arsenyev begins the investigation. In the number of suspects fall all — after all, we are talking about a huge legacy of the old master. But the result of the investigation is unexpected even for an experienced detective.
Dr. Grunert, electronics specialist from the GDR, gets a visit from an old acquaintance from war times. Both worked back then on navy torpedoes. His former colleague wants to poach Grunert – to Schenectady, the headquarters of the largest American electronics company. With alleged war crimes, he tries to blackmail Grunert, but quickly it becomes clear where the true criminals are sitting: In influential positions of the American industry. Grunert underestimates the scrupulousness of his opponent and invites him to a remotely located country home to clarify things. The Ministry for State Security is already on the trail of the matter and saves the engineer from a dangerous solo action.
A group of young scientists conducts an experiment, putting themselves in the conditions of the people of the Stone Age. With the help of stone tools, they procure food and fire, and make themselves comfortable in nature.
