A group of former classmates rent a country house to relax like in the good old days. The modern chalet has everything for a comfortable and fun vacation, including the smart speaker "Alyona". "Alyona" knows how to entertain her guests, she has many "skills". She can solve puzzles, manage the house, and she also knows all the "skeletons in the closet" that friends are hiding. The device invites the company to play the game "Find the Killer" and find out the circumstances of the death of their best friend, who died less than a year ago under strange circumstances.

The aftermath of a shocking explosion at the Chernobyl nuclear power station made hundreds of people sacrifice their lives to clean up the site of the catastrophe and to successfully prevent an even bigger disaster that could have turned a large part of the European continent into an uninhabitable exclusion zone. This is their story.