It was two hundred yards below where they were standing; and a hundred yards beyond the tepee he saw where it came out of a great rent in the mountain.
He looked at Joanne.

She had been watching him, and was breathing quickly.
"While Donald is taking his look from the mountain, I'm going to investigate the chasm," he said.
She followed him, a few steps behind.

The roar grew in their ears as they advanced.

After a little solid rock replaced the earth under their feet, and twenty paces from the precipice Aldous took Joanne by the hand.

They went to the edge and looked over.