"Is it so?" he asked, and he too made sure by a comparison with his own watch that Frobisher's statement was correct. "Yes. Twenty-three minutes past one. That is very fortunate."
He called Ann Upcott and Moreau to him and they all now stood grouped about the cabinet.
"The key to the mystery about this clock," he remarked, "is to be found in the words which Mademoiselle Ann used, when the seals were removed from the doors and she saw this clock again, in the light of day. She was perplexed. Isn't that so, Mademoiselle?"
"Yes," Ann returned. "It seemed to me—it seems to me still—that the clock was somehow placed higher than it actually is——"
"Exactly. Let us put it to the test!"
He looked at the clock and saw that the hands now reached twenty-six minutes past one.
"I will ask you all to go out of this room and wait in the hall in the dark. For it was in the dark, you will remember, that Mademoiselle descended the stairs. I shall turn the lights out here and call you in. When I do, Mademoiselle will switch the lights on and off swiftly, just as she did it on the night of the 27th of April. Then I think all will be clear to you."
He crossed to the door leading into the hall, and found it locked with the key upon the inside.
"Of course," he said, "when the passage is used to the Hôtel de Brebizart, this door would be locked."
He turned the key and drew the door towards him. The hall gaped before them black and silent. Hanaud stood aside.