“What an honour to my poor house!” he exclaimed.  “How unworthy am I to receive such august guests!”

“We’ve come to see if you have any more crystals like the one I bought of you to-day, Mustapha,” I said.

“Alas! honoured patron, none!” cried Mustapha in a relieved voice, thinking that he now knew the object of our visit.

“Think—­think, Mustapha,” said I.  “Have you no piece of clear glass that could be used in its place?”

[Illustration:  “I took up the stone.”]

“Alas, none!” he replied, shaking his head.

“Look about,” said I.  “Here in the shop—­and down in the cellar.”

The little man’s face turned green.

“The cellar?  Noble patron, how should I find such a thing there?”

“Lead the way and I will try to show you,” said I; and despite his agonised protests, the trembling wretch was made to lead us to the very spot where the jewel was hidden.

I took up the stone and showed the Magistrate the box in which the diamond was concealed, while Mustapha grovelled on the ground, pleading for mercy.

What followed was a matter of course.  The merchant Mustapha was arrested, I was released and commissioned to let Shin Shira know that if he applied in person for his jewel it would be returned to him, and an apology offered for his unwarranted arrest.

And so I was set free—­a stranger and alone in Baghdad.

MYSTERY NO.  VII

SHIN SHIRA AND THE ROC

When I found myself alone in Baghdad after my extraordinary adventure with the Magic Crystal, my first intention was to return at once to England.

I found, however, that it would be impossible for me to do so for at least four days; so I prepared to make the best of matters by doing a little sight-seeing while I was still confined to the ancient and interesting city.

There were two additional reasons which made the delay less disagreeable to me.

The first one was that I might possibly happen to meet Shin Shira again before I departed; and the other was that, on the second day of my stay, I saw a printed notice to the effect that, according to the ancient usage of the country relating to condemned prisoners, all of Mustapha’s goods were to be immediately sold by public auction, and the money realised was to be confiscated by the Crown.

I had noticed a number of very quaint and curious articles in the shop, and thought that it would be an excellent opportunity for me to purchase some souvenirs of my visit, to take back with me to England.

The sale took place the next day, and I was able to secure several interesting pieces, which have a place in my study to this day.  In fact, I was tempted to buy so many things that I began to fear that I should soon not have enough money left to take me back again to London; and I was just about to leave the auction, in order to be out of the way of temptation, when I caught sight of the quaintest, most uncanny-looking brass lamp being offered for sale that you could possibly imagine.