They passed on from stone to stone until they came to the subterranean chamber itself.  Without a moment’s hesitation, Wu made his way toward the rock in which they had found the slot with its cryptic inscription.

Long Sin watched his master in silent admiration as, at last, he drew forth the mystic ring for which they had dared all.

Without a word, Wu dropped it in the slot.  It tinkled down the runway, a protuberance hit a trigger and pushed it a hair’s breadth.

A noise behind them caused the two to turn startled.  Even Wu had not expected it.

On the other side of the chamber, a great rock in the ground slowly turned, as though on a pivot.  They watched, fascinated.  Even then Wu did not forget the precious ring, but as the rock turned, reached down quickly and recovered it from the cup at the floor.

Inch by inch the pivoted rock moved on its axis.  They flashed their lanterns full on it and, as it moved, they could see disclosed huge piles of gold and silver in coins and bars and ornaments, a chest literally filled with brilliants, set and unset, rubies, emeralds, precious stones of every conceivable variety, a cave that would have staggered even Aladdin—­the rich reward of the countless marauding operations of Bennett’s other personality.

For a moment they could merely stand in avaricious exultation.

. . . . . . .

Painfully and slowly, we managed to trail Long Sin’s footprints, until we came to a road where they were lost in the hard macadam.  There was no time to stop.  We must follow the road on the chance that he had taken it.  But which way?

Kennedy chose the most likely direction, for the trail had been at an angle to the road and Long Sin was not likely to double back.  We had not gone many rods before Kennedy paused a minute and looked about in the moonlight.

“It’s right, Walter,” he cried.  “Do you recognize it?”

I looked about.  Then it flashed over me.  This was the back road that led past the entrance to the treasure vault at Aunt Tabby’s.

We went on now more quickly, listening carefully to catch any sounds, but heard nothing.  At last Kennedy stopped, then plunged among the rocks and bushes beside the road.  We were at the cave.

“You go in this way, Walter,” he directed.  “I’ll go around and down where it caved in.”

I groped my way along through the darkness.

I had gone only a yard or two, when it seemed as though something had grasped my foot.

With a great wrench I managed to pull it loose.  But the weight on my other foot had imbedded it deeper.  I struggled to free this foot and got the other caught.  My revolver, which I had drawn, was jarred from my hand and in the effort to recover it, I lost my balance.  Unable to move a foot in time to catch myself, I fell forward.  My hands were now covered by the slimy, sticky stuff, and the more I struggled, the worse I seemed to get entangled.