“I’d rather go hungry,” I declared, washing my hands and arms in the cool water.

“Oh, sure,” said Harry; “my efforts are never appreciated.  I’ve fed you up till you’ve finally graduated from the skeleton class, and you immediately begin to criticize the table.  I know now what it means to run a boarding-house.  Why don’t you change your hotel?”

By the time we had finished we were pretty well tired out, but Harry wouldn’t hear of rest.  I was eager myself for another look at the exit of that stream.  So, again taking up our spears, we set out across the cavern, this time with Desiree between us.  She swallowed Harry’s ridicule of her fear and refused to stay behind.

Again we stood at the point where the stream left the cavern through the broad arch of a tunnel.

“There’s a chance there,” said Harry, turning to me.  “It looks good.”

“Yes, if we had a boat,” I agreed.  “But that’s a ten-mile current, and probably deep.”

I waded out some twenty feet and was nearly swept beneath the surface as the water circled about my shoulders.

“We couldn’t follow that on our feet,” I declared, returning to the shore.  “But it does look promising.  At ten miles an hour we’d reach the western slope in four hours.  Four hours to sunshine—­but it might as well be four hundred.  It’s impossible.”

We turned then and retraced our steps to our camp, if I may give it so dignified a title.  I hated to give up the idea of following the bed of the stream, for it was certain that somewhere it found the surface of the earth, and I revolved in my brain every conceivable means to do so.  The same thought was in Harry’s mind, for he turned to me suddenly: 

“If we only had something for stringers, I could make a raft that would carry us to the Pacific and across it.  The hide of that thing over yonder would be just the stuff, and we could get a piece as big as we wanted.”

I shook my head.

“I thought of that.  But we have absolutely nothing to hold it.  There wasn’t a bone in his body; you know that.”

But the idea was peculiarly tempting, and we spent an hour discussing it.  Desiree was asleep on her pile of skins.  We sat side by side on the ground some distance away, talking in low tones.

Suddenly there was a loud splash in the stream, which was quite close to us.

“By gad!” exclaimed Harry, springing to his feet.  “Did you hear that?  It sounded like—­remember the fish we pulled in from the Inca’s raft?”

“Which has nothing to do with this,” I answered.  “It’s nothing but the water-pigs.  I’ve heard ’em a thousand times in the last few days.  And the Lord knows we have enough of them.”

But Harry protested that the splash was much too loud to have been caused by any water-pig and waded into the stream to investigate.  I rose to my feet and followed him leisurely, for no reason in particular, but was suddenly startled by an excited cry from his lips: