Kesselbach must have defended himself …”

“No, because he was bound.”

“That’s true,” owned Gourel, somewhat disconcertedly, “and it’s rather curious too … Why kill an adversary who has practically ceased to exist? … But, no matter, if I had collared him yesterday, when we were face to face at the hall-door …”

M. Lenormand had stepped out on the balcony. Then he went to Mr. Kesselbach’s bedroom, on the right, and tried the fastenings of the windows and doors.

“The windows of both rooms were shut when I came in,” said Gourel.

“Shut, or just pushed to?”

“No one has touched them since. And they are shut, chief.”

A sound of voices brought them back to the sitting-room. Here they found the divisional surgeon, engaged in examining the body, and M. Formerie, the magistrate. M. Formerie exclaimed:

“Arsène Lupin! I am glad that at last a lucky chance has brought me into touch with that scoundrel again! I’ll show the fellow the stuff I’m made of! … And this time it’s a murder! … It’s a fight between you and me now, Master Lupin!”

M. Formerie had not forgotten the strange adventure of the Princesse de Lamballe’s diadem, nor the wonderful way in which Lupin had tricked him a few years before. The thing had remained famous in the annals of the law-courts. People still laughed at it; and in M. Formerie it had left a just feeling of resentment, combined with the longing for a striking revenge.

“The nature of the crime is self-evident,” he declared, with a great air of conviction, “and we shall have no difficulty in discovering the motive. So all is well … M. Lenormand, how do you do? … I am delighted to see you …”

M. Formerie was not in the least delighted. On the contrary, M. Lenormand’s presence did not please him at all, seeing that the chief detective hardly took the trouble to disguise the contempt in which he held him. However, the magistrate drew himself up and, in his most solemn tones:

“So, doctor, you consider that death took place about a dozen hours ago, perhaps more! … That, in fact, was my own idea … We are quite agreed … And the instrument of the crime?”

“A knife with a very thin blade, Monsieur le Juge d’Instruction,” replied the surgeon. “Look, the blade has been wiped on the dead man’s own handkerchief …”

“Just so … just so … you can see the mark … And now let us go and question Mr. Kesselbach’s secretary and man-servant. I have no doubt that their examination will throw some more light on the case.”

Chapman, who together with Edwards, had been moved to his own room, on the left of the sitting-room, had already recovered from his experiences. He described in detail the events of the previous day, Mr. Kesselbach’s restlessness, the expected visit of the Colonel and, lastly, the attack of which they had been the victims.

“Aha!” cried M. Formerie. “So there’s an accomplice! And you heard his name! … Marco, you say? … This is very important. When we’ve got the accomplice, we shall be a good deal further advanced …”

“Yes, but we’ve not got him,” M. Lenormand ventured to remark.

“We shall see … One thing at a time … And then, Mr. Chapman, this Marco went away immediately after M. Gourel had rung the bell?”

“Yes, we heard him go.”

“And after he went, did you hear nothing else?”

“Yes … from time to time, but vaguel … The door was shut.”

“And what sort of noises did you hear?”

“Bursts of voices.