“Mercy!” he exclaimed; “what a disappointment that will be to Poole! He declared that millions in gold were buried in that cavern.”

“So his avarice is repaid,” said Frank, with a laugh. “Poor wretch! Let him have his treasure and all the good it may do him.”

“Then you will not interfere?”

“Certainly not.”

“Good,” cried Wade. “Let us then go on to Yucatan and finish our exploration of the sunken isthmus. We will leave Mr. Poole to the exclusive enjoyment of his much-vaunted treasure.”

“Just so,” said Frank. “Start the engines, Barney; let us get under way.”

Barney hastened to obey. As the Diver sailed away to the westward the searchlight was focused upon the cavern mouth.

There a curious scene was revealed.

Poole and his men were digging in the sands for the coins scattered by the Caribs. They seemed to act like madmen, so strong was the treasure fever upon them.

The submarine voyagers were glad to leave the sunken Isle of Mona behind them. The Diver glided on through the deep sea.