lay concealed for weeks at a time.  The old gentleman gave me a solemn assurance that the secret existed with him alone; all who had been in any way implicated in the earlier troubles having died long ago.  As the property had now become mine by purchase, he thought it only right that before he died these facts should be brought to my knowledge.  You may imagine, my dear Ducie, with what eagerness I seized upon this place as a safe depository for my diamond, which, up to this time, I had been obliged to carry about my person.  And now, forward to the heart of the mystery!”

Having unlocked and flung open the second iron door, Platzoff took up his lamp, and, closely followed by Ducie, entered a narrow winding passage in the rock.  After following this passage, which tended slightly downwards for a considerable distance, they emerged into a large cavernous opening in the heart of the hill.

Platzoff’s first act was, by means of a long crook, to draw down within reach of his hand a large iron lamp that was suspended from the roof by a running chain.  This lamp he lighted from the hand-lamp he had brought with him.  As soon as released, it ascended to its former position, about ten feet from the ground.  It burned with a clear white flame that lighted up every nook and cranny of the place.  The sides of the cave were of irregular formation.  Measuring by the eye, Ducie estimated the cave to be about sixty yards in length, by a breadth, in the widest part, of twenty.  In height it appeared to be about forty feet.  The floor was covered with a carpet of thick brown sand, but whether this covering was a natural or an artificial one Ducie had no means of judging.  The atmosphere of the place was cold and damp, and the walls in many places dripped with moisture; in other places they scintillated in the lamplight as though thousands of minute gems were embedded in their surface.

In the middle of the floor, on a pedestal of stones loosely piled together, was a hideous idol, about four feet in height, made of wood, and painted in various colours.  In the centre of its forehead gleamed the great Diamond.

“Behold!” was all that Platzoff said, as he pointed to the idol.  Then they both stood and gazed in silence.

Many contending emotions were at work just then in Ducie’s breast, chief of which was a burning, almost unconquerable desire to make that glorious gem his own at every risk.  In his ear a fiend seemed to be whispering.

“All you have to do,” it seemed to say, “is to grip old Platzoff tightly round the neck for a couple of minutes.  His thread of life is frail and would be easily broken.  Then possess yourself of the Diamond and his keys.  Go back by the way you came and fasten everything behind you.  The household is all a-bed, and you could get away unseen.  Long before the body of Platzoff would be discovered, if indeed it were ever discovered, you would be far away and beyond all fear of pursuit.  Think!  That tiny stone is worth a hundred and fifty thousand pounds.”