The Persian did not reply. He fetched a stool and set it against the wall facing the great mirror that filled the whole of the wall-space opposite. Then he climbed on the stool and, with his nose to the wallpaper, seemed to be looking for something.

“Ah,” he said, after a long search, “I have it!”

And, raising his finger above his head, he pressed against a corner in the pattern of the paper. Then he turned round and jumped off the stool:

“In half a minute,” he said, “we shall be on his road !” and crossing the whole length of the dressing-room he felt the great mirror.

“No, it is not yielding yet,” he muttered.

“Oh, are we going out by the mirror?” asked Raoul. “Like Christine Daaé.”

“So you knew that Christine Daaé went out by that mirror?”