"Stone Heart" is a detective melodramatic mini-series. Journalist Galina is going through a difficult separation from her husband. She immerses herself in her work to cope with the pain. But one day, she suffers a professional setback: the subject of her article, businessman Andreev, accuses her of defamation and takes her to court. Galina decides to prove her innocence at all costs and searches for a witness - doctor Mikhail, whose wife died due to Andreev's fault. However, the man is not eager to give an interview.