Achille gave a cry of amazement. But Lupin objected:
“Well? And what then? We are no better off than before. Here is an empty oblong, eight or nine inches wide by sixteen inches high. You’re not going to pretend that a woman can slip through an opening which would not admit the thinnest child of ten years old!”
“No, but she can have put her arm through and drawn the bolts.”
“The bottom bolt, yes,” said Lupin. “But the top bolt, no: the distance is far too great. Try for yourself and see.”
Achille tried and had to give up the attempt.
Lupin did not reply. He stood thinking for a long time. Then, suddenly, he said:
“Give me my hat . . . my coat....”
He hurried off, urged by an imperative idea. And, the moment he reached the street, he sprang into a taxi:
“Rue Matignon, quick!...”
As soon as they came to the house where he had been robbed of the crystal stopper, he jumped out of the cab, opened his private entrance, went upstairs, ran to the drawing-room, turned on the light and crouched at the foot of the door leading to his bedroom.