“Then this may be our chance,” Jack suggested. His gaze fastened upon the filing cabinet. “Why not?”

“It’s probably locked.”

“Probably,” Jack agreed. He tried the wooden drawer, and to his surprise, it pulled open.

Stuffed into the back of the file were samples of rock and a bottle of chemical. Manila folders were stacked in the front, each neatly labeled. However, nearly all were empty of papers.

“Rhodes must have cleaned out about everything,” Jack commented. “Nothing here apparently, except routine letters.”

He pulled out a second drawer, entirely empty except for a long roll of heavy paper, tied with cord. Impelled by curiosity, he untied the knot and spread out the sheet.

“Why, it’s a map!” he exclaimed. “A map of an emerald mine!”

“This one?” Mr. Livingston demanded. Getting up, he went to the desk to peer over Jack’s shoulder.

The map was roughly drawn, but to scale. Even a casual glance convinced the two that it was not a representation of the Last Chance mining operation.

“It seems to be located across the stream,” Jack said, his interest growing. “In the densely forested area. You don’t suppose—”