thirty feet
in diameter, with a height of some twenty feet. There was but one
entrance, that by which they had come, but high up on the wall were
several small openings or tunnel-like passages. Around the wall of the
chamber was a row of skeletons, standing stiffly upright. There was a
great roughly hewed stone god or idol on the farther side, while here
and there close around it on the surface of the natural stone floor were
marks where fires had been built. At either side were pyramidial walls
of human skulls, all perfect, though those that formed the bottom rows
were black with age.

As the light from the torches flashed into the space several large bats
that were in the openings began to fly wildly about.

"I wonder where they have gone?" said Tom, gazing blankly around. "There
was certainly something that had hold of me, but there isn't anything
here now."

"What was it like?" asked Jim, suddenly.

"How should I know," returned Tom. "I couldn't see it in the dark."

"But you could feel it, couldn't you?" persisted Jim.

"Why," returned Tom, "I don't know, just like any person I should say."

"And you, Jo," went on Jim. "What was yours like?"

"Why, like anybody, I suppose," was the somewhat indefinite description.

"Now, what is the matter?" demanded Tom, as Jim dropped to the floor in
a paroxysm of laughter.

"Oh, ho, ho. It's too funny for anything," returned Jim in intervals of
his merriment.

"What is?" demanded Tom.

"The whole business," returned Jim as he struggled to regain control of
his feelings.

"Let us in on the funny part," said Tom, a little sourly.

"Well, you see, when you dropped the torch--"

"You mean that's the time we didn't see," put in Tom.

"One of those big bats flopped into your face--."

"Well?"

"Then you two started to run, and, of course, you ran into each other
and thought something had gotten hold of you. Oh, ho, ho!" and once more
Jim was doubled up in his paroxysms of merriment.

"I guess you are right, Jim," said Jo, somewhat sheepishly, but joining
in the laugh. "I think the joke is on us."

"What is this place anyhow?" asked Tom, seeking to change the
embarrassing subject. "Was it an underground prison?"

"I think it was a burial place of some tribe," replied Jim, when he was
able to control his laughter. "You see the skeletons are all standing up
in like positions as if they were placed there after death."

"What are the bats doing in here?"

"The