Notwithstanding this statement, the king made vigorous exertions to discover the perpetrators of the crime. The following facts were soon brought to light. The king, some time before, much displeased with the Chevalier de Lorraine, a favorite and adviser of Monsieur, angrily arrested him, and imprisoned him in the Chateau d'If, a strong and renowned fortress on Marguerite Island, opposite Cannes. Here he was treated with great rigor. He was not allowed to correspond, or even to speak with any persons but those on duty within the fortress. _Monsieur_ was exceedingly irritated by this despotic act. He ventured loudly to upbraid his brother, and bitterly accused _Madame_ of having caused the arrest of his bosom friend, the chevalier. Circumstances directed the very strong suspicions of the king to M. Pernon, controller of the household of the princess, as being implicated in the murder. The king ordered him to be secretly arrested, and brought by a back staircase to the royal cabinet. Every attendant was dismissed, and his majesty remained alone with the prisoner. Fixing his eyes sternly upon the countenance of M. Pernon, Louis said, "If you reveal every circumstance relative to the death of _Madame_, I promise you full pardon. If you are guilty of the slightest concealment or prevarication, your life shall be the forfeit." The controller then confessed that the Chevalier de Lorraine had, through the hands of a country gentleman, M. Morel, who was not at all conscious of the nature of the commission he was fulfilling, sent the poison to two confederates at St. Cloud. This package was delivered to the Marquis d'Effiat and Count de Beuvron, intimate friends of the chevalier, and who had no hope that he would be permitted to return to Paris so long as _Madame_ lived. The Marquis d'Effiat contrived to enter the closet of the princess, and rubbed the poison on the inside of the enameled cup from which Henrietta was invariably accustomed to drink her favorite beverage. The king listened intently to this statement, pressed his forehead with his hand, and then inquired, in tones which indicated that he was almost afraid to put the question, "And _Monsieur_--was he aware of this foul plot?" "No, sire," was the prompt reply. "_Monsieur_ can not keep a secret; we did not venture to confide in him." Louis appeared much relieved. After a moment's pause, he asked, with evident anxiety, "Will you swear to this?" "On my soul, sire," was the reply. The king asked no more. Summoning an officer of the household, he said, "Conduct M. Pernon to the gate of the palace, and set him at liberty."