Young lawyer Agata Rud did not expect that her new client would be a friend of her beloved grandmother. It turns out that Ekaterina Mellina is suspected of murdering her friend, which happened in her apartment. When Ekaterina was away, someone poured poison into the teapot... The murdered Olga Voronina was not only a friend, but also a colleague of Mellina’s at a research institute studying the capabilities of the human brain. After interviewing Voronina’s subordinates, Agata found out what the investigator was too lazy to find out: that morning Olga met an old acquaintance who used to work at the institute, but she didn’t have time to name his name... But it was at this research institute that Agata’s father, who had disappeared for many years, once worked back. Now lawyer Rudy has a personal interest in this case - having found the real killer, she will reveal all the family secrets!