He was standing at the open front of a great case which stood between the windows and which contained part of his Chinese collection. He turned as I entered with a small brown vase in his hand.

“Pray sit down, Doctor,” said he. “I was looking over my own treasures and wondering whether I could really afford to add to them. This little Tang specimen, which dates from the seventh century, would probably interest you. I am sure you never saw finer workmanship or a richer glaze. Have you the Ming saucer with you of which you spoke?”

I carefully unpacked it and handed it to him. He seated himself at his desk, pulled over the lamp, for it was growing dark, and set himself to examine it. As he did so the yellow light beat upon his own features, and I was able to study them at my ease.

He was certainly a remarkably handsome man. His European reputation for beauty was fully deserved. In figure he was not more than of middle size, but was built upon graceful and active lines. His face was swarthy, almost Oriental, with large, dark, languorous eyes which might easily hold an irresistible fascination for women. His hair and moustache were raven black, black the latter short, pointed, and carefully waxed. His features were regular and pleasing, save only his straight, thin-lipped mouth. If ever I saw a murderer’s mouth it was there — a cruel, hard gash in the face, compressed, inexorable, and terrible. He was ill-advised to train his moustache away from it, for it was Nature’s danger-signal, set as a warning to his victims. His voice was engaging and his manners perfect. In age I should have put him at little over thirty, though his record afterwards showed that he was forty-two.

“Very fine — very fine indeed!” he said at last. “And you say you have a set of six to correspond. What puzzles me is that I should not have heard of such magnificent specimens. I only know of one in England to match this, and it is certainly not likely to be in the market. Would it be indiscreet if I were to ask you, Dr. Hill Barton, how you obtained this?”

“Does it really matter?” I asked with as careless an air as I could muster.

“You can see that the piece is genuine, and, as to the value, I am content to take an expert’s valuation.”

“Very mysterious,” said he with a quick, suspicious flash of his dark eyes. “In dealing with objects of such value, one naturally wishes to know all about the transaction. That the piece is genuine is certain. I have no doubts at all about that. But suppose — I am bound to take every possibility into account — that it should prove afterwards that you had no right to sell?”

“I would guarantee you against any claim of the son.”

“That, of course, would open up the question as to what your guarantee was worth.”

“My bankers would answer that.”

“Quite so. And yet the whole transaction strikes me as rather unusual.”

"Don't you think, monsieur le secretaire-general, that this broken bit of ivory which was picked up on the ground... "

"No, M. Nicole, no. That bit of ivory belongs to something which we do not know and which its owner will at once make it his business to conceal. In order to trace the owner, we should at least be able to define the nature of the thing itself."

M. Nicole reflected and then began:

"Monsieur le secretaire-general, when Napoleon I fell from power... "

"Oh, M. Nicole, oh, a lesson in French history!"

"Only a sentence, monsieur le secretaire-general, just one sentence which I will ask your leave to complete. When Napoleon I fell from power, the Restoration placed a certain number of officers on half-pay. These officers were suspected by the authorities and kept under observation by the police. They remained faithful to the emperor's memory; and they contrived to reproduce the features of their idol on all sorts of objects of everyday use; snuff-boxes, rings, breast-pins, pen-knives and so on."

"Well?"

"Well, this bit comes from a walking-stick, or rather a sort of loaded cane, or life-preserver, the knob of which is formed of a piece of carved ivory. When you look at the knob in a certain way, you end by seeing that the outline represents the profile of the Little Corporal. hat you have in your hand, monsieur le secretaire-general, is a bit of the ivory knob at the top of a half-pay officer's life-preserver."

"Yes," said Prasville, examining the exhibit, "yes, I can make out a profile... but I don't see the inference... "

"The inference is very simple. Among Daubrecq's victims, among those whose names are inscribed on the famous list, is the descendant of a Corsican family in Napoleon's service, which derived its wealth and title from the emperor and was afterward ruined under the Restoration. It is ten to one that this descendant, who was the leader of the Bonapartist party a few years ago, was the fifth person hiding in the motor-car. Need I state his name?"

"The Marquis d'Albufex?" said Prasville.

"The Marquis d'Albufex," said M. Nicole.

M. Nicole, who no longer seemed in the least worried with his hat, his glove and his umbrella, rose and said to Prasville:

"Monsieur le secretaire-general, I might have kept my discovery to myself, and not told you of it until after the final victory, that is, after bringing you the list of the Twenty-seven. But matters are urgent. Daubrecq's disappearance, contrary to what his kidnappers expect, may hasten on the catastrophe which you wish to avert. We must therefore act with all speed. Monsieur le secretaire-general, I ask for your immediate and practical assistance."

"In what way can I help you?" asked Prasville, who was beginning to be impressed by his quaint visitor.

"By giving me, to-morrow, those particulars about the Marquis d'Albufex which it would take me personally several days to collect."

Prasville seemed to hesitate and turned his head toward Mme. Mergy. Clarisse said:

"I beg of you to accept M. Nicole's services. He is an invaluable and devoted ally. I will answer for him as I would for myself."