"Can ye see anything, Mac?" inquired the wielder of the pick, pausing in his labours, and glancing eagerly at his companion.

"I'm simply flabbergasted," came the slow response. "There seems to be enough gold there to stock a second Bank o' England."

He picked up a piece of the strange formation which showed dazzling yellow lines across its newly broken face, and examined it closely and intently; he rubbed it with his finger, and the brilliance vanished.

"We'd better take up some o' the best-looking bits," he suggested.

Bill laughed. "Why, the hanged stuff won't show a colour on top," he said.

But they decided to chance it all the same, and accordingly Mackay arrived on the surface bearing the result of his investigations tightly wrapped in an old handkerchief, and when the package was opened up a cry of admiration broke from all beholders, so beautiful, indeed, did the specimens appear.

A hoarse call from the underground interrupted their scrutiny.

"For Heaven's sake, boys, put a chain on that there mirage, until I get a look at it."

And while two men went to the windlass and began to haul Bill to the surface, a gradual change began to take place in the nature of the specimens. The yellow sheen grew darker and darker until it shone like bronze, and in this state Bill viewed them on his arrival. Slowly yet surely the bronze shades merged into a strangely variegated purple hue, and, while the onlookers stared aghast, this gradually evolved into the original clayey aspect of the formation surrounding it.

"Well, I'll be jiggered!" ejaculated the Shadow.