He was always talking of waging war against Henry de Valois, and he was called "Captain Clement." He told a story about a vision he had of an angel, who had bidden him "to put to death the tyrant of France, in return for which he would have the crown of martyrdom." Royalist writers report that he had been placed in personal communication with the friends of Henry de Guise, even with his sister the Duchess of Montpensier, and his brother the Duke of Mayenne.

When well informed of the facts, the King of Navarre returned to his quarters at Meudon, and Rosny to his lodging at the foot of the castle.

Whilst Rosny was at supper, his secretary came and said to him, "Sir, the King of Navarre, peradventure the King of France, wants you.

M.d'Orthoman writes to him to make haste and come to St.Cloud if he would see the king alive." The King of Navarre at once departed.

Just as he arrived at St.Cloud, he heard in the street cries of "Ah! my God, we are lost!" He was told that the king was dead.