"No, I haven't the least idea; but if I ever get hold of him, I shall know what to do!" The Marquis smiled and shrugged his shoulders: "I shall be glad to help you." "Thanks, Monsieur le Marquis, but I'm afraid we shan't succeed. There's a French detective on the case, a man named Juve, who hasn't been able to find the man either!" The Marquis gave a slight start: "Ah, and Juve has found nothing, suspects nobody?" "No." "That is strange.... Well, Monsieur Wulf, I think we shall be able to do better. You are ready for anything?" "For everything, on my honor!" replied Wulf, with fervor. "Very well, then I promise you we shall have some news within a week. But excuse me a moment, I have some orders to give; I won't be a moment." The Marquis crossed the room and opened the door; Wulf could hear him talking: "Is that you, Madame Ceiron?" A woman's voice answered: "Yes, Monsieur le Marquis. What can I do for you?" "Kindly unpack the bag in my room and when you go out be sure to lock the doors. I don't want a recurrence of what happened the other day when some one entered my apartment and left a chemise belonging to the murderer among my laundry." "Monsieur le Marquis may rest assured his orders will be obeyed." In a few moments the Marquis returned and M. Wulf rose to go. He repeated with emphasis his determination: "If ever I get the chance to arrest this murderer, I will do so in the face of any danger. All for the King! That is my motto!" "Yes, you are right, Monsieur, all for the King." The Marquis de Serac bowed his visitor out, and then suddenly his smiling face underwent an astounding change of expression. "I must clinch my alibi!" In a moment he had torn off his false whiskers and his wig of white hair was quickly replaced by another--this time a woman's wig. With the agility of a Fregoli he then got into a skirt and waist. Forty seconds after the departure of Wulf the Marquis de Serac had become ... Madame Ceiron, the concierge. Three or four pencil marks and his disguise was complete. It would be impossible for anybody not having seen this transformation to guess that the Marquis de Serac and old Madame Ceiron were one and the same individual. After a quick glance into his mirror he rushed across his drawing-room, through the hall, and quickly opened a large Breton wardrobe. Through the centre of this rose a post which he seized and slid down. It was the same contrivance used by firemen to join their engines when a call was sent in. At the foot of the post in Madame Ceiron's apartment were stretched two mattresses to deaden the fall. These were placed in a small storeroom, well hidden from observation. After closing the door behind her, Madame Ceiron rushed to the hall in time to intercept Wulf on his way downstairs. "You are looking for some one?" she asked. "No, Madame, I have just come from the Marquis de Serac's apartment."