It is finally revealed why Meshchersky was conducting the experiment. Katya discovers a whole new side of herself.

Katya's traumatic past becomes known. The relationship between the girl and Victor Anatolievich also becomes clearer.

Investigators continue to unravel the complex case and are now looking not only for the professor, but also for an unknown criminal.

Investigators are scrutinizing the details of Meshchersky's experiment. The professor himself is in a difficult position.

All the participants of the experiment realize that there is a connection between them. It becomes known what happened to Natasha.

An experiment goes completely off track, and a big disaster occurs. The eight participants are trapped and looking for a way out.

The professor is approached by the police with inquiries. One of the participants in the experiment gives everyone an unpleasant surprise. 

An ambitious professor of psychiatry begins an unusual experiment. He gathers victims and their abusers in the same building.