The world famous expert Drongo is back in action. This time, high authorities from the FSB convincingly ask the detective to help his colleagues from Serbia. The local prosecutor's office is struggling with the mysterious murder of the country's Deputy Prime Minister Predrag Bastic. He was strangled in his own mansion during a very important meeting of government officials from all the Balkan republics. Bashtic's bodyguard was arrested on suspicion of murder, but it is unlikely that this was his doing. Drongo finds out that on the day of the murder there were four people in the mansion who should not have been at this secret meeting. And one of them is Bashtic’s son...