`I do not understand you. You treat him as a monster, you speak of his crime, he has done you harm and I find in you the same inexplicable pity that drove me to despair when I saw it in Christine!'

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, `he shall be on his road!' and crossing the whole 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?'

`She did so before my eyes, sir! I was hidden behind the curtain of the inner room and I saw her vanish not by the glass, but in the glass!'

`And what did you do?'

`I thought it was an aberration of my senses, a mad dream.

`Or some new fancy of the ghost's!' chuckled the Persian. `Ah, M. de Chagny,' he continued, still with his hand on the mirror, `would that we had to do with a ghost! We could then leave our pistols in their case....Put down your hat, please...there... and now cover your shirt-front as much as you can with your coat... as I am doing....Bring the lapels forward...turn up the collar....We must make ourselves as invisible as possible.'

Bearing against the mirror, after a short silence, he said:

`It takes some time to release the counterbalance, when you press on the spring from the inside of the room. It is different when you are behind the wall and can act directly on the counterbalance. Then the mirror turns at once and is moved with incredible rapidity.'

`What counterbalance?' asked Raoul.

`Why, the counterbalance that lifts the whole of this wall on to its pivot. You surely don't expect it to move of itself, by enchantment! If you watch, you will see the mirror first rise an inch or two and then shift an inch or two from left to right. It will then be on a pivot and will swing round.'

`It's not turning!' said Raoul impatiently.

`Oh, wait! You have time enough to be impatient, sir! The mechanism has obviously become rusty, or else the spring isn't working....Unless it is something else,' added the Persian, anxiously.

`What?'

`He may simply have cut the cord of the counterbalance and blocked the whole apparatus.'

`Why should he? He does not know that we are coming this way!'

`I dare say he suspects it, for he knows that I understand the system.'