"Excuse me, Monsieur Jacques, one question before anything else," said Rouletabille.

"What is it, young man? If I can answer it—"

"Did your mistress wear her hair in bands, that evening? You know what I mean—over her forehead?"

"No, young man. My mistress never wore her hair in the way you suggest, neither on that day nor on any other. She had her hair drawn up, as usual, so that her beautiful forehead could be seen, pure as that of an unborn child!"

Rouletabille grunted and set to work examining the door, finding that it fastened itself automatically. He satisfied himself that it could never remain open and needed a key to open it. Then we entered the vestibule, a small, well-lit room paved with square red tiles.

"Ah! This is the window by which the murderer escaped!" said Rouletabille.

"So they keep on saying, monsieur, so they keep on saying! But if he had gone off that way, we should have been sure to have seen him. We are not blind, neither Monsieur Stangerson nor me, nor the concierges who are in prison. Why have they not put me in prison, too, on account of my revolver?"

Rouletabille had already opened the window and was examining the shutters.

"Were these closed at the time of the crime?"

"And fastened with the iron catch inside," said Daddy Jacques, "and I am quite sure that the murderer did not get out that way."

"Are there any blood stains?"

"Yes, on the stones outside; but blood of what?"

"Ah!" said Rouletabille, "there are footmarks visible on the path—the ground was very moist. I will look into that presently."

"Nonsense!" interrupted Daddy Jacques; "the murderer did not go that way."

"Which way did he go,