ing in the rock was of such extent that the ceiling was scarcely visible above in the light of the flash.
"I don't know where we're going, but we're on our way," said Frank, as they toiled on up over the rough rocks. His voice awakened tumultuous echoes that were flung back and forth from the massive walls.
The flashlight showed him at length a place where the floor dipped abruptly to a steep slope, although there was still a wide ledge at the top, sufficiently wide for them to proceed. He turned the light down the slope but could see nothing save inky blackness.
The boys proceeded slowly along the ledge.
There were numerous pebbles and small rocks underfoot. It was difficult to see these, because Frank was obliged to keep the flashlight centered on the trail ahead, and they were obliged to proceed cautiously in order to keep their footing. This circumstance led to disaster.
Unwittingly, Frank stepped on a small rock that rolled suddenly beneath his foot. He staggered, stepped on another rock that slipped to one side and then he sprawled forward, the flashlight spinning from his hand.
The light clattered among the rocks ahead and darkness fell about them.
"What's the matter?" asked Joe, alarmed.
