When the British millionaire Mornington dies of blood poisoning in Morocco, his friend Don Luis Perenna is appointed to manage the estate. The task is to find the heirs of a fortune of 100 million francs within three months. Unfortunately, it seems that someone is intent on eliminating all potential heirs before Perenna can contact them. Thus, Don Luis, supported by the French police, must confront this sinister adversary. In particular, an attractive young woman is in grave danger. But Perenna wouldn't be Perenna if he couldn't turn the game to his advantage through some unconventional tricks - or is he actually someone entirely different, someone we have come to know well by now? A new translation of the classic crime novel by Maurice Leblanc by the renowned crime and young adult author.