“If we find the place,” Roy had asked in their flight in the early dawn, “do you look for trouble?”

“Them old grandpa baldies?” answered Weston, as if surprised. “They ain’t got a gun among ’em.”

It was the first day of September. The depressing monotony of the lifeless plains was accentuated by a choking dust. The rose tints of early days had disappeared in a dead blue, cloudless sky. The heat seemed to penetrate to the lungs and brain.

“There’s the Escalante,” said Roy a half hour after Clark’s camp was left.

“Now fur the south,” added Weston in a dry, harsh voice. “Hold her true an’ don’t ye stop till ye see somepin, ef it takes us acrost Arizony.”

The great wonder was, how Weston had missed finding the hole in his several searches. Within five miles of where the aeroplane turned south from the river, the mysterious hole suddenly appeared directly beneath the swiftly sailing Parowan. No dark depths greeted the approaching eye. What had at first seemed but a slight depression in the desert suddenly became a large circular shaft. The fumes of sulphur had colored its sides a yellowish white.

The Parowan came to a stop several hundred yards beyond the hole. Too excited to return in the airship, Weston and the boy sprang to the sand and started on a run back to the chasm. Then they discovered that their path lay along the dry bed of a watercourse.

“That’s it,” exclaimed Weston. “This is my river bed. But it comes from the south. It comes off the Straight Cliffs. I allers reckoned it come out o’ the west. An’ I sarched mainly along the Sevier Range.”

In a few moments they reached the point where the river bed ended in a worn gully leading down to the top rock shelf of the Sink Hole. Weston sprang into the depression, and, Roy at his heels, was soon on the rough, rocky shoulder that dropped, screw-like, lower and lower toward the north face of the circular opening.