He had reached the place where Chet and Diane lay and saw the beginning of the tower's fall; and in the split second of its falling he threw himself across the body of the prostrate girl to shield her from flying fragments of stone. A blast of air tore at him; his ears were numbed with the thunder of the blast—a thunder that ended with a crashing of stone on stone....
lowly he recovered his breath; then raised himself to his feet to look toward the entrance. It would be open now, the way cleared. But, instead of sunlight, he saw utter dark. Where the mouth of the cave had been was blackness—and nothing else!
He fumbled for his flash, and stood in despairing silence before what the light disclosed.
The rock was black and shining about the mouth of the cavern. It had split like glass. In shattered fragments it filled the forward part of the cave. The whole roof must have fallen, and a crashing slide above had covered all.
Chet was beside him; Harkness dared not look toward the girl coming expectantly forward.
"We'll use more of the same," Chet suggested: "we will blast our way out."
"And bring down more rock with each charge," Harkness told him tonelessly. "This means we are—"
Diane had overheard. Harkness' pause had come too late.