The boy picked out one large piece, and, exerting all his strength, tore it away from the wall.

He then carried it to the cavern and tossed it upon the burning coals, about ten feet away from the end of the passage.
Then he returned for another fragment of rock, and wrenching it free from its place, he threw it ten feet beyond the first one, toward the opposite side of the cave.

The boy continued this work until he had made a series of stepping-stones reaching straight across the cavern to the dark passageway beyond, which he hoped would lead him back to safety if not to liberty.
When his work had been completed, Inga did not long hesitate to take advantage of his stepping-stones, for he knew his best chance of escape lay in his crossing the bed of coals before the rocks became so heated that they would burn his feet.

So he leaped to the first rock and from there began jumping from one to the other in quick succession.

A withering wave of heat at once enveloped him, and for a time he feared he would suffocate before he could cross the cavern; but he held his breath, to keep the hot air from his lungs, and maintained his leaps with desperate resolve.
Then, before he realized it, his feet were pressing the cooler rocks of the passage beyond and he rolled helpless upon the floor, gasping for breath.