The silence was prolonged.  Don Luis waited patiently.  Then, suddenly, the Prefect stopped and said: 

“When you left the Boulevard Richard-Wallace, Monsieur, did you go straight home?”

Don Luis did not demur to this cross-examining manner and answered: 

“Yes, Monsieur le Prefet.”

“Here, to your study?”

“Here, to my study.”

M. Desmalions paused and then went on: 

“I left thirty or forty minutes after you and drove to the police office in my car.  There I received this express letter.  Read it.  You will see that it was handed in at the Bourse at half-past nine.”

Don Luis took the letter and read the following words, written in capital letters: 

This is to inform you that Gaston Sauverand, after making his escape, rejoined his accomplice Perenna, who, as you know, is none other than Arsene Lupin.  Arsene Lupin gave you Sauverand’s address in order to get rid of him and to receive the Mornington inheritance.  They were reconciled this morning, and Arsene Lupin suggested a safe hiding-place to Sauverand.  It is easy to prove their meeting and their complicity.  Sauverand handed Lupin the half of the walking-stick which he had carried away unawares.  You will find it under the cushions of a sofa standing between the two windows of Perenna’s study.

Don Luis shrugged his shoulders.  The letter was absurd; for he had not once left his study.  He folded it up quietly and handed it to the Prefect of Police without comment.  He was resolved to let M. Desmalions take the initiative in the conversation.

The Prefect asked: 

“What is your reply to the accusation?”

“None, Monsieur le Prefet.”

“Still, it is quite plain and easy to prove or disprove.”

“Very easy, indeed, Monsieur le Prefet; the sofa is there, between the windows.”

M. Desmalions waited two or three seconds and then walked to the sofa and moved the cushions.  Under one of them lay the handle end of the walking-stick.

Don Luis could not repress a gesture of amazement and anger.  He had not for a second contemplated the possibility of such a miracle; and it took him unawares.  However, he mastered himself.  After all, there was nothing to prove that this half of a walking-stick was really that which had been seen in Gaston Sauverand’s hands and which Sauverand had carried away by mistake.

“I have the other half on me,” said the Prefect of Police, replying to the unspoken objection.  “Deputy Chief Weber himself picked it up on the Boulevard Richard-Wallace.  Here it is.”

He produced it from the inside pocket of his overcoat and tried it.  The ends of the two pieces fitted exactly.

There was a fresh pause.  Perenna was confused, as were those, invariably, upon whom he himself used to inflict this kind of defeat and humiliation.  He could not get over it.  By what prodigy had Gaston Sauverand managed, in that short space of twenty minutes, to enter the house and make his way into this room?  Even the theory of an accomplice living in the house did not do much to make the phenomenon easier to understand.