Down in the ocean depths, Poole and his men had been at work digging out the supposed mighty treasure of the Isle of Mona.

Every skeleton was unearthed and the sand around it closely sifted. Thus the coins were recovered.

Also further excavations were made in the cavern, but without success.

However, believing the coins to be gold, the villain was fairly well satisfied. He piled them into the chest and had it hoisted aboard the schooner.

“Ha,” he muttered, “I was just in time to foil those dogs. They were sure of beating me, but Hardy Poole has staked too much upon this game to lose. Curse them, 43I will some day have a chance to settle the score with them.”

With this venomous decision he removed his diving-suit and had begun to examine his treasure when an incident occurred.

One of the men who had been in the shrouds cried:

“Sail ho!”

“What?” cried Poole, with a sudden start. “Bearing our way?”

“Yes.”

“What does she look like?”

“She looks like a fast craft, sir. Most likely a coast guard vessel,” was the reply.

“Change course. Bear nor’-nor’-west!” ordered the villain. “We don’t want to fall in with any Cuban cruiser just now.”

The schooner lay about on the new course. She was a fairly fast sailer and cut the water rapidly.

But in a few moments the man aloft again shouted:

“Ahoy, the chase!”

“Eh?” roared Poole. “Is she giving us a chase?”

“That she is, sir, and she is gaining on us. She has steam up and can sail two knots to our one.”

“A steam vessel!” gasped Poole. “Then she is certainly a Cuban cruiser. She takes us for a filibuster. If she overtakes us nothing will convince her that we are not and our jig is up! Ho, there, all aloft and crowd on sail! We must make a run for it! If she overhauls us——”

“Well?” asked one of the men.

Poole’s grim face hardened.

“We will fight for it!” he said, “for they will never take the treasure from us while we live.”

The crew cheered at this bold declaration and then scampered aloft. Meanwhile Poole watched the distant steamer with varied sensations.

“Just our luck,” he muttered. “By the gods, I believe I am cursed by fate! Let them overhaul us, curse them! We will give them all the fight they want.”

Then he went back to the cabin and began to gloat over the treasure. He picked up one of the coins and scraped away the rust and mold. Then he snapped his eyes.

How was this?

It was white metal instead of yellow—silver instead of gold!

If all that bulk of coin was silver, its value was but small; if of gold, it would be immense. Quite a difference. He dropped the coin with a grunt.

He picked up another and scratched its surface. It was also silver.

44Another and another. Then a sickening sensation came over him, and he smiled in a ghastly way.

“Silver!” he hissed. “Can all of them be such? Is there no gold?”

He kept at his work. It soon became apparent to him that this was a terrible fact. He sank in a chair, with distorted features and bursting veins.

For a moment he was apoplectic. Then great curses rolled from his lips. He struck the table with his clenched hand.

“They have beaten me!” he hissed; “they have taken the gold and left me the silver! Curse them! they have beaten me, but the end is not yet!”

He was too unreasonable to consider the situation logically. He could accept but one conclusion, and this was that the submarine voyagers had taken the gold and outwitted him.

“Why did I allow them to escape me?” he gritted. “I should have killed them all! They were in my power! Fool! Fool!”

He raved like a maniac in his impotent wrath, frothed at the mouth, and might have really yielded to apoplexy or some other fit had not an interruption come.

The distant boom of a gun was heard. Poole turned a ghastly pallor.

He knew what that meant.

“They are overhauling us!” he gritted. “We are to lose even this pittance of silver! But I will have the gold if I have to follow Frank Reade, Jr., to the end of the earth!”

He hastened upon deck.

The cruiser had come up within gunshot and had sent a summons to heave-to. There was no alternative but to obey or fight or go to the bottom.

For a moment Poole considered seriously the question of a fight. He would gladly have accepted it had the conditions been anywhere near equal.

But the cruiser had heavier guns and more men. There was no other course but to heave-to.

So the schooner came up to the wind, her mainsail slacked, and the two vessels drifted within speaking distance.

“Ahoy, the schooner!” came the hail in Spanish. The Cuban flag was seen to be flying at the yard of the cruiser.

“Ahoy!” replied Poole.

“What craft is that?”

“The Meta; pleasure yacht, under the United States flag,” replied Poole.

For a time there seemed to be a consultation held aboard the cruiser. Then another hail came:

45“Captain of the Meta, we are going to send our lieutenant aboard you!”

“What is that?” shouted Poole. “We are under the protection of the United States flag. I warn you not to trouble us!”

A jeering laugh came back.

“Lower your gangway,” was the reply.

Then a boat slid down from the Santa Maria’s davits and six men entered it. One ............