"Quite."

He listened again:

"The secretary to the head of the criminal investigation department? Oh, excellent! Mr. Secretary, I have on several occasions been in communication with M. Dudouis and have given him information which has been of great use to him. He is sure to remember Prince Renine. I may be able to-day to show him where the sixty thousand-franc notes are hidden which Aubrieux the murderer stole from his cousin. If he's interested in the proposal, beg him to send an inspector to the Bra.s.serie Lutetia, Place des Ternes. I shall be there with a lady and M. Dutreuil, Aubrieux's friend. Good day, Mr.

Secretary."

When Renine hung up the instrument, he saw the amazed faces of Hortense and of Gaston Dutreuil confronting him.

Hortense whispered:

"Then you know? You've discovered ...?"

"Nothing," he said, laughing.

"Well?"

"Well, I'm acting as though I knew. It's not a bad method. Let's have some lunch, shall we?"

The clock marked a quarter to one.

"The man from the prefecture will be here," he said, "in twenty minutes at latest."

"And if no one comes?" Hortense objected.

"That would surprise me. Of course, if I had sent a message to M. Dudouis saying, 'Aubrieux is innocent,' I should have failed to make any impression. It's not the least use, on the eve of an execution, to attempt to convince the gentry of the police or of the law that a man condemned to death is innocent. No. From henceforth Jacques Aubrieux belongs to the executioner. But the prospect of securing the sixty bank-notes is a windfall worth taking a little trouble over. Just think: that was the weak point in the indictment, those sixty notes which they were unable to trace."

"But, as you know nothing of their whereabouts...."

"My dear girl--I hope you don't mind my calling you so?--my dear girl, when a man can't explain this or that physical phenomenon, he adopts some sort of theory which explains the various manifestations of the phenomenon and says that everything happened as though the theory were correct. That's what I am doing."

"That amounts to saying that you are going upon a supposition?"

Renine did not reply. Not until some time later, when lunch was over, did he say:

"Obviously I am going upon a supposition. If I had several days before me, I should take the trouble of first verifying my theory, which is based upon intuition quite as much as upon a few scattered facts. But I have only two hours; and I am embarking on the unknown path as though I were certain that it would lead me to the truth."

"And suppose you are wrong?"

"I have no choice. Besides, it is too late. There's a knock. Oh, one word more! Whatever I may say, don't contradict me. Nor you, M. Dutreuil."

He opened the door. A thin man, with a red imperial, entered:

"Prince Renine?"

"Yes, sir. You, of course, are from M. Dudouis?"

"Yes."

And the newcomer gave his name:

"Chief-inspector Morisseau."

"I am obliged to you for coming so promptly, Mr. Chief-inspector," said Prince Renine, "and I hope that M. Dudouis will not regret having placed you at my disposal."

"At your entire disposal, in addition to two inspectors whom I have left in the square outside and who have been in the case, with me, from the first."

"I shall not detain you for any length of time," said Renine, "and I will not even ask you to sit down. We have only a few minutes in which to settle everything. You know what it's all about?"

"The sixty thousand-franc notes stolen from M. Guillaume. I have the numbers here."

Renine ran his eyes down the slip of paper which the chief-inspector handed him and said:

"That's right. The two lists agree."

Inspector Morisseau seemed greatly excited:

"The chief attaches the greatest importance to your discovery. So you will be able to show me?..."

Renine was silent for a moment and then declared:

"Mr. Chief-inspector, a personal investigation--and a most exhaustive investigation it was, as I will explain to you presently--has revealed the fact that, on his return from Suresnes, the murderer, after replacing the motor-cycle in the shed in the Avenue du Roule, ran to the Ternes and entered this house."

"This house?"

"Yes."

"But what did he come here for?"

"To hide the proceeds of his theft, the sixty bank-notes."

"How do you mean? Where?"

"In a flat of which he had the key, on the fifth floor."

Gaston Dutreuil exclaimed, in amazement:

"But there's only one flat on the fifth floor and that's the one I live in!"

"Exactly; and, as you were at the cinema with Madame Aubrieux and her mother, advantage was taken of your absence...."

"Impossible! No one has the key except myself."

"One can get in without a key."

"But I have seen no marks of any kind."

Morisseau intervened: