“The museum has been robbed!” I cried, springing up in bed.

“I fear so! Those jewels! The jewels of the urim and thummim!” he gasped, for he was out of breath with running. “I’m going on to the police-station. Come to the museum as soon as you can, Jackson! Good-bye!” He rushed distractedly out of the room, and I heard him clatter down the stairs.

I was not long in following his directions, but I found when I arrived that he had already returned with a police inspector, and another elderly gentleman, who proved to be Mr. Purvis, one of the partners of Morson and Company, the well-known diamond merchants. As an expert in stones he was always prepared to advise the police. They were grouped round the case in which the breastplate of the Jewish priest had been exposed. The plate had been taken out and laid upon the glass top of the case, and the three heads were bent over it.

“It is obvious that it has been tampered with,” said Mortimer. “It caught my eye the moment that I passed through the room this morning. I examined it yesterday evening, so that it is certain that this has happened during the night.”

It was, as he had said, obvious that some one had been at work upon it. The settings of the uppermost row of four stones—the carnelian, peridot, emerald, and ruby-were rough and jagged as if some one had scraped all round them. The stones were in their places, but the beautiful gold-work which we had admired only a few days before had been very clumsily pulled about.

“It looks to me,” said the police inspector, “as if some one had been trying to take out the stones.”

“My fear is,” said Mortimer, “that he not only tried, but succeeded. I believe these four stones to be skilful imitations which have been put in the place of the originals.”

The same suspicion had evidently been in the mind of the expert, for he had been carefully examining the four stones with the aid of a lens. He now submitted them to several tests, and finally turned cheerfully to Mortimer.

“I congratulate you, sir,” said he, heartily. “I will pledge my reputation that all four of these stones are genuine, and of a most unusual degree of purity.”

The colour began to come back to my poor friend’s frightened face, and he drew a long breath of relief.