Sieur d’Eon de Mouloize, who should take charge of the documents in the event of the discovery of the scheme. As for the technical part, it was to be entrusted to an engineer, Carrelet de la Rozière. Lastly, the basis of a cypher to be employed in the affair was arranged. The King gave his instructions himself: The Chevalier d’Eon will receive through the Comte de Broglie or M. Tercier my orders on the surveys to be made in England, whether on the coast or in the interior of the country, and he will comply with the instructions he will receive to that end, as if he received them direct from me. It is my desire that he shall observe the greatest secrecy in this affair, and that he shall not make any communications thereon to any living person, not even to my ministers wheresoever they may be. These instructions were precisely stated and commented upon by the Comte de Broglie in a letter which he sent, on May 7, 1763, to the Chevalier d’Eon in London. He recommended him to observe the utmost prudence in his conduct, apprising him that the Comte de Guerchy’s suspicious character would render his secret mission extremely difficult, and urged him to take every conceivable precaution for the safety of the papers connected with the correspondence. The Count appointed him tutor to M. de la Rozière, adding: “He is a somewhat wild pupil, but you will be pleased with him.” In conclusion he congratulated himself upon having d’Eon as “lieutenant in so important an affair, which may contribute to the safety and even to the prosperity of the nation,” and thanked him for the zeal and devotion which he had never ceased to show to the Marshal de Broglie and to himself. D’Eon’s attachment to the exiled de Broglies had awakened the suspicions of the Duc de Praslin, and the Minister for Foreign Affairs did not hesitate to subject the young representative of the King at the court of St. James’ to a regular interrogatory, in the presence of his senior clerk, Sainte-Foy, and the Comte de Guerchy. He began by abruptly asking him to give an account of the battle of Villinghausen, at which he was present while serving in the dragoons. D’Eon did not require much pressing, and boldly laid to the charge of Soubise all the blunders officially imputed to the Duc de Broglie. Praslin, who was striding impatiently up and down the room, suddenly interrupted him, exclaiming: “I know it to have been just the opposite of what you say, and this from one of my intimate friends who was also there.” And he turned to the Comte de Guerchy. “But, my dear d’Eon, you surely did not witness all you tell me.”