“But how in the mischief,” thought he, “am I to find anything here?” He held up his lantern and looked about.  “I can’t move these rocks to see what is under them.”

As he gazed around, he noticed that the southeast corner seemed to be more regular than the rest of the wall of the cave.  In fact, it was almost a right-angled corner, and seemed to have been roughly cut into that shape.  Instantly Burke was in the corner.  He found the eastern wall quite smooth for a space about a foot wide and extending about two yards from the floor.  In this he perceived lines of crevice marking out a rectangular space some six inches wide and four feet in height.

“Ha, ha!” cried Burke.  “The handle is on the other side of that slab, I’ll bet my head!” And putting down the lantern, he went to work.

With his hammer and chisel he had forced the top of the slab in less than two minutes, and soon he pulled it outward and let it drop on the floor.  Inside the narrow, perpendicular cavity which was now before him, he saw an upright metal bar.

“The handle of the bolt!” cried Burke.  “Now I can unfasten the trap-door.”  And taking hold of the top of the bar, he pulled back with all his force.  At first he could not move it, but suddenly the resistance ceased, and he pulled the bar forward until it stood at an angle of forty-five degrees from the wall.  Further than this Burke could not move it, although he tugged and bore down on it with all his weight.

“All right,” said he, at last.  “I guess that’s as far as she’ll come.  Anyway, I’m off to see if I’ve drawn that bolt.  If I have, I’ll have that trap-door open, if I have to break my back lifting it.”

With his best speed Burke ran through the caves to the mound, and, mounting by means of the stone projections, he was about to descend by the ladder, when, to his utter amazement, he saw no ladder.  He had left it projecting at least two feet through the opening in the top of the mound, and now he could see nothing of it.

What could this mean?  Going up a little higher, he held up his lantern and looked within, but saw no signs of the ladder.

“By George!” he cried, “has anybody followed me and pulled out that ladder?”

Lowering the lantern farther into the mound, he peered in.  Below, and immediately under him, was a black hole, about three feet square.  Burke was so startled that he almost dropped the lantern.  But he was a man of tough nerve, and maintained his clutch upon it.  But he drew back.  It required some seconds to catch his breath.  Presently he looked down again.

“I see,” said he.  “That trap-door was made to fall down, and not to lift up, and when I pulled the bolt, down it went, and the ladder, being on top of it, slipped into that hole.  Heavens!” he said, as a cold sweat burst out over him at the thought, “suppose I had made up my mind to cut that bolt!  Where would I have gone to?”