We were completely stunned by the cataclysm, but in a moment Harry had recovered and run to the edge of the chasm opposite thus suddenly formed. Desiree and I followed.
There was nothing to be seen save the blackness of space. Immediately before us was an apparently bottomless abyss, black and terrifying; the side descended straight down from our feet. Looking across we could see dimly a wall some distance away, smooth and with a faint whiteness. On either side of us other walls extended to meet the farther wall, smooth and polished as glass.
"The Incas didn't do that, I hope," said Harry, turning to me.
"Hardly," I answered; and in my absorbing interest in the phenomenon before me I half forgot my pain.
I moved to the edge of one of the walls extending at right angles to the passage, but there was little to be made of it. It was of soft limestone, and most probably the portion that had disappeared was granite, carried away by the force of its own weight.
"We are like to be buried," I observed, returning to Harry and Desiree. "Though for that matter, even that can hardly frighten us now."
"For my part," said Harry, with a curious gravity beneath the apparent lightness of his words, "I have always admired the death of Porthos. Let it come, and welcome."
"Are we to go further?" put in Desiree.
Just as Harry opened his mouth to reply a more decisive answer came from another source. The rock that had fallen, obstructing the path of the Incas, must have left an opening that Harry had missed; or they had removed it—what matter?
In some way they had forced a passage, for as Desiree spoke a dozen spears whistled through the air past our heads and we looked up to see a swarm of Incas climbing and tumbling down the face of a boulder over which we had passed to reach our resting-place.