“Ah!” he exclaimed. “Here you are—all sound except for a cracked arm.”

“What happened?” I asked.

He grinned at me. “Why, we were all helping at the water-hole when Van Dusee missed you. He remembered that you had been standing by the stone column one minute; the next you were gone, absolutely vanished, just as if the earth had opened up and swallowed you.”

“Which in fact it had,” I said, grimly. “But wasn’t the top open?”

“Open!” shouted Anderson. “I should say not. Hardy and I hammered that pile of stone and we couldn’t make a dent in it. We never thought of trying the top. Finally Hardy slipped a little dynamite under the column and we followed you down the stairway.”

By degrees I got my strength back.

“Ready for some big news?” Anderson said, presently.

I nodded.

“All right, then. Hang on now. We came to South America to get scientific data, didn’t we?”