“Go ahead and finish up the details, such as installing the lining,” he said. “We didn’t get this far to be stopped now.”

But the prospecting parties, making full use of the time left them before winter closed down, returned late that fall to report no sign of the ore they needed.

Spring came and he was determined they would be smelting aluminum before the summer was over even though he had no idea where the ore would be found. They needed aluminum ore of a grade high enough that they could extract the pure aluminum oxide. Specifically, they needed aluminum oxide.⁠ ⁠…

Then he saw the answer to their problem, so obvious that all of them had overlooked it.

He passed by four children playing a game in front of the caves that day; some kind of a checker-like game in which differently colored rocks represented the different children. One boy was using red stones; some of the rubies that had been brought back as curios from the chasm. Rubies were of no use or value on Ragnarok; only pretty rocks for children to play with.⁠ ⁠…

Only pretty rocks?⁠— rubies and sapphires were corundum, were pure aluminum oxide!

He went to tell George and to arrange for a party of men to go into the chasm after all the rubies and sapphires they could find. The last obstacle had been surmounted.