Drongo, a world-renowned expert on crime, came to an international conference in Romania. Already on the second day, he learns that several summit participants received threatening letters. The unknown person warned them of an unknown danger, and hinted that this was connected with the spirit of Count Dracula. Almost everyone, including Drongo, believes that this is just a stupid prank. However, when two forum guests suddenly die, the expert changes his mind and takes the matter seriously...