Mr. Duke was naturally eager to learn details of the new development, and in less than half an hour he joined the others in Mr. Williams’s office. French explained the situation, ending up, “Now we want you, Mr. Duke, to tell us if these were among the stones you lost.”

The diamond merchant, obviously much excited, began at once to make his examination. He inspected the stones minutely through a lens, weighed them on a delicate balance he had brought, and put them to other tests which greatly interested his companions. As he put each down he gave his judgment. One after another were identified. All were among those stolen from him. They were the sixteen smallest and least valuable stones of the collection.

The fact was learned by the three men with very different emotions. Mr. Duke’s gain was Mr. Williams’s loss, and resulting satisfaction and consternation showed on their respective faces, while French’s countenance wore an expression of the liveliest delight, not unmixed with mystification.

“Good heavens!” Mr. Williams cried, his voice trembling with agitation and excitement. “Then I’ve been swindled! Swindled out of three thousand pounds!” He glared at the Inspector as if he were at fault. “I suppose,” he continued, “that if this gentleman establishes his claim, the loss will fall on me? God knows, I can ill afford it.”

“We shall hope not, sir,” French said sympathetically. “We shall hope that with luck you’ll recover your money. But we must not waste any more time. I shall start by going to the bank to see if all the money has been withdrawn. I’d be obliged, Mr. Williams, if you would come also. I’ll keep you advised, Mr. Duke, how things go on, and of course you’ll get back your stones after the usual formalities have been carried out.”

Mr. Williams had recovered his composure, and, the gems having been locked in his safe, the three men left the office and descended to the street. There French said good-day to Mr. Duke, who somewhat reluctantly took his leave, the other two continuing to the bank. After a few moments’ wait they were shown into the manager’s room.

“I am afraid, Mr. Scarlett, I have had a serious misfortune,” Mr. Williams began, almost before they were seated. “I have just learned that I have been swindled out of £3000. This is Inspector French of Scotland Yard, and we both want your help in the matter.”

Mr. Scarlett, a well-groomed, middle-aged gentleman of fashionable appearance and suave manners, looked suitably concerned. He shook hands with French, and expressed his commiseration with his client’s loss in a few easy words, declaring also his desire to be of service.

“Do you remember,” Mr. Williams went on eagerly, “my coming to see you one morning about six weeks ago with a lady whom I introduced as Mrs. Root, of Pittsburg, U. S. A.? She held my cheque for £3000, and I came to introduce her to you.”

The manager recalled the incident.