“Exactly!” said a jubilant voice behind them, and Mr. Isidore Le Drieux stepped forward and calmly drew up a chair, in which he seated himself.  “You will pardon me, gentlemen, for eavesdropping, but I was curious to know what you thought of this remarkable young man who calls himself ‘A.  Jones.’”

Arthur faced the intruder with a frown.  He objected to being startled in this manner.  “You are a detective?” he asked.

“Oh, scarcely that, sir,” Le Drieux replied in a deprecating way.  “My printed card indicates that I am a merchant, but in truth I am a special agent, employed by the largest pearl and gem dealers in the world, a firm with branches in every large European and American city.  My name is Le Drieux, sir, at your service,” and with a flourish he presented his card.

The young rancher preferred to study the man’s face.

“I am a sort of messenger,” he continued, placidly.  “When valuable consignments of jewels are to be delivered, I am the carrier instead of the express companies.  The method is safer.  In twenty-six years of this work I have never lost a single jewel.”

“One firm employs you exclusively, then?”

“One firm.  But it has many branches.”

“It is a trust?”

“Oh, no; we have many competitors; but none very important.  Our closest rival, for instance, has headquarters on this very coast—­in San Francisco—­but spreads, as we do, over the civilized world.  Yet Jephson’s—­that’s the firm—­do not claim to equal our business.  They deal mostly in pearls.”

“Pearls, eh?” said Arthur, musingly.  “Then it was your firm that lost the valuable collection of pearls you mentioned to Mr. Merrick?”

“No.  They were the property of Countess Ahmberg, of Vienna.  But we had sold many of the finest specimens to the countess and have records of their weight, size, shape and color.  The one you are now wearing, sir,” pointing to Uncle John’s scarf pin, “is one of the best black pearls ever discovered.  It was found at Tremloe in 1883 and was originally purchased by our firm.  In 1887 I took it to Tiffany, who sold it to Prince Godesky, of Warsaw.  I carried it to him, with other valuable purchases, and after his death it was again resold to our firm.  It was in October, 1904, that I again became the bearer of the pearl, delivering it safely to Countess Ahmberg at her villa.  It was stolen from her, together with 188 other rare pearls, valued at a half million dollars, a little over a year ago.”

“This pearl, sir,” said Uncle John stiffly, “is not the one you refer to.  It was found on the shores of the island of Sangoa, and you have never seen it before.”

Le Drieux smiled sweetly as he brushed the ashes from his cigar.

“I am seldom mistaken in a pearl, especially one that I have handled,” said he.  “Moreover, a good pearl becomes historic, and it is my business to know the history of each and every one in existence.”