"Yes. Why?" Frobisher asked eagerly.
Hanaud shrugged his shoulders.
"The letters were burned. It is difficult to say. For my part I think those old letters between Simon Harlowe and Madame Raviart alluded too often to the secret passage. But here I am guessing. What I learnt for certain during that luncheon hour is that there is a secret passage and that it runs from the treasure-room to the Hôtel de Brebizart. For this time Nicolas Moreau makes no mistake. He follows her to the Hôtel de Brebizart and I from this tower see the smoke rising from the chimney. Look, Monsieur, there it is! But no smoke rises from it to-day."
He rose to his feet and turned his back upon Mont Blanc. The trees in the garden, the steep yellow-patterned roof, and the chimneys of the Maison Crenelle stood out above the lesser buildings which surrounded them. Only from one of the chimneys did the smoke rise to-day, and that one at the extreme end of the building where the kitchens were.
"We are back then in the afternoon. The seals are removed. We are in Madame Harlowe's bedroom and something I cannot explain occurs."
"The disappearance of the necklace," Frobisher exclaimed confidently; and Hanaud grinned joyfully.
"See, I set a trap for you and at once you are caught!" he cried. "The necklace? Oh, no, no! I am prepared for that. The guilt is being transferred to Mademoiselle Ann. Good! But it is not enough to hide the book about the arrow in her room. No, we must provide her also with a motive. Mademoiselle is poor; Mademoiselle inherits nothing. Therefore the necklace worth a hundred thousand pounds vanishes, and you must draw from its vanishing what conclusion you will. No, the little matter I cannot explain is different. Betty Harlowe and our good Girardot pay a visit to Jeanne Baudin's bedroom to make sure that a cry from Madame's room could not be heard there."
"Yes."
"Our good Girardot comes back."
"Yes."