The mere motion caused the horrid pile to disintegrate and relapse into a heap of gray dust.

Ages had passed since these bones had been deposited there, as this very action would attest.

‪“Come away,” said Frank, with a shiver. “Let’s find our way out of here.”

Together they passed by the heap of moldering bones.

A deep, arched passage lay before them. It was not a long one, and suddenly came to an end in a startling manner.

A huge iron gate made of transverse bars confronted them.

It was a ponderous affair, and there were huge bolts to hold it shut.

It did not seem as if they could ever hope to pass through it.

‪“My soul, we are badly stuck!” cried Tony. “We’ll never get out of here alive, Frank.”

Frank looked aghast.