Noir De La Roche’s black diamond, Black Cliff, was stolen from a prince who arrived in Moscow from Central Africa in the 19th century. A precious stone was stolen by his servant-interpreter, with whom the nobleman traveled through Russia. They did not have time to bring the fraudster to justice, but they found his dead body .. Diamond irretrievably disappeared, but soon got to the famous thief Sonka Golden Pen … Investigator Sergei Dulo came to the restaurant to meet with the famous lawyer Susanna Milkina, but suddenly in a luxurious hall there was an explosion … Milkina died, and Sergei miraculously survived and took an active part in the investigation of the explosion. In the past, Susanna found very unsightly episodes, one of which featured the murder of the famous actress, a star of Soviet cinema, and the kidnapping of her priceless black diamond.