Then Christine, whom he recognized by the sound of her voice, closed the door behind them and warned him, in a whisper, to remain at the back of the box and on no account to show himself.

Raoul took off his mask.

Christine kept hers on.

And, when Raoul was about to ask her to remove it, he was surprised to see her put her ear to the partition and listen eagerly for a sound outside.

Then she opened the door ajar, looked out into the corridor and, in a low voice, said: "He must have gone up higher." Suddenly she exclaimed: "He is coming down again!" She tried to close the door, but Raoul prevented her; for he had seen, on the top step of the staircase that led to the floor above, A RED FOOT, followed by another ...