Perhaps the least of all affected by what had taken place was the giant. Gold meant nothing to him. To serve Tom Swift was his whole aim in life. Born in a savage country, he had not acquired an overwhelming desire for wealth.

Consequently he was cool enough as he tore another box from the many that were fitted into the safe. The water had swelled the wood, and it was not easy to get them out.

A pressure of the giant's iron bar broke the sealed lid. On top was the same layer of gold pieces, but when the box was emptied the same trick was discovered. Iron disks made up the remainder of the contents.

"Bilked! That's what I call it! Regularly bilked!" exclaimed one of the divers, an Englishman who had been in Tom's service several years. "Somebody's got the cream of this pudding before we did!"

"I'm inclined to agree with you," said Tom. "Unless it transpires that not all the boxes have been thus camouflaged. We must take time to examine."

Then began a period of hard work. Laboring in relays of divers, every box that had been locked in the purser's safe was brought out on the submerged cabin table, broken open, and the contents examined. The hoax was even worse than indicated at first. For after the front section of boxes had been taken out none of the others remaining contained any gold at all. There were only iron disks.

"Well, Tom, what do you think of it?" asked Ned of his chum, when they had returned to the cabin of the submarine, leaving some members of the crew to complete the examination. For this the diving bell was used, as well as the suits.

"I don't think very much," was the answer. "It looks as though we had been sold."

"Do you think Hardley knew that the gold had been changed to iron--that is, all but a small part of it?"

"No, I don't believe he did," Tom answered. "If he were here I'd warrant he would be as much surprised as we are. He certainly believed the Pandora was a regular treasure-ship."

"Just how much did she really have in gold?" asked Mr. Damon, looking at the double eagles on the table of the M. N. 1.

"Well, at a rough guess I'd say ten thousand dollars," Tom answered. "We haven't brought it all out yet, and it's possible they may find a full box in the safe. But, unless there is one, I guess ten or fifteen thousand dollars will cover it."

"And Hardley said two millions!" exclaimed Ned. "Whew, what a difference!"

"Do you think he was in on the change?" asked one of the officers.

"No," replied Tom. "I guess it was like a good many of these filibustering plots. Somebody put up good money to be used to gain control of a country--perhaps for the country's good. But somebody else made the substitution, and the patriots were left. I don't believe Hardley knew this."

"Well, you'll get a little out of it, Tom," Ned remarked.

"Nothing worth while," was the answer. "But I'm not disappointed; that is, very much. Of course I could use the money, but I don't really need it. The trip has been a wonderful experience, and I have learned something I didn't know before. I'm sorry for you, though, Mr. Damon. You invested considerable with Hardley, didn't you?"

"About twenty thousand dollars, Tom. It will be hard to lose it, but I guess I can stand it."

Tom privately made up his mind to see that his old friend did not suffer financially, for the gold discovered on the Pandora, while it was far from the amount hoped for, would almost reimburse Mr. Damon. But the young inventor did not say anything about that just then.

They were looking at the recovered gold and getting ready to store it in some of the boxes that had been brought from the wreck when the divers that had remained on the Pandora to bring the last of the treasure returned through the chamber. Two of them carried a small steel box.

"What's that?" asked Tom, when they had their helmets off.

"Don't know," was the answer. "It was in the purser's safe. Stuck away in the far corner."

"Maybe it has jewels in it!" exclaimed Ned. "If it has--"

At that moment the lookout who had maintained his position in the conning tower called for Tom on the telephone.

"What is it?" asked the young inventor.

"There's some sort of grappling iron, or cable with a hook on it, being lowered from the surface, and it's near the wreck," was the answer. "If it isn't any of your apparatus it may be some other ship having a try for the gold."

"It must be Hardley!" cried Tom. "He's come back with another ship, as he half threatened to do, and, instead of diving for the wreck, which he can't get ordinary men to do in this depth, he's trying to grapple for it. Come on, we'll have a look!"

Ned and Mr. Damon followed Tom to the conning tower. Looking out through the heavy glass windows, while the searchlight illuminated the waters, the young inventor and his friends saw a great grappling iron swaying this way and that through the sea not far from the wreck, and once, indeed, uncomfortably close to their own craft.

"He's struck it uncommonly near," remarked Tom. "I guess it's time for us to be leaving."

"Suppose it's Hardley up above there?" suggested Ned.

"I don't doubt but it is."

"Well, are we going off and leave the wreck--and possibly other gold that may be hidden on her?"

"I wouldn't give ten dollars for the chance of searching for any more gold!" Tom exclaimed. "We'll take this steel box--it may contain something of value. The rest we'll leave to Hardley."

Preparations for rising to the surface were quickly made. Up and up went the M. N. 1, leaving the ill-starred Pandora to whatever else fate had in store for her.

Tom's craft broke water with gentle undulations of the waves. The top of the hatch was thrown back, admitting the bright sunshine on those who had been long in the shadow of the underseas. And, as the young inventor and his friends went out on deck, they saw a small steamer riding on the ocean not far away.

One look was enough to tell them it was from this craft that the grappling iron had been let down, and as the submarine drifted nearer the form of Hardley was seen on deck. He was directing operations.

Some one must have called his attention to the M. N. 1, for he hurried to the rail of the craft which he had evidently chartered to seek the Pandora, and he exclaimed:

"What are you doing here, Swift?"

"The same thing you are, I believe," coolly answered Tom. "Cleaning up the treasure ship. You might as well save your money though, for we have all the gold there is!"

"Impossible!" cried the now irate man. "You cannot have found the Pandora!"

"That's just what we did, though," answered Tom. "And, for your information, I'll say that we took all the gold we found, though it was considerably less than you stated."

"How dare you?" stormed the adventurer. "I'll have the law on you for this!"

"I guess you forget," replied Tom, "that we parted company at your request and that I told you I was on my own. Finding is keeping. I didn't find what I expected to, and, on the other hand, I got something I didn't look for."

"What do you mean

"The Pandora was rightly named," went on Tom. "If you recall the old story, Pandora had a box of treasures. They all flew out except Hope, which remained in the bottom. Well, most of the gold seems to have flown away, but we found a box on the Pandora. What's in it I don't know yet, as I haven't opened it. Still, if it doesn't contain more than Hope I shall be disappointed."

The face of Hardley showed the rage felt.

"Give me that box! Give me that box!" he cried, shaking his fist at Tom.

"Not today," was the cool answer of the young inventor. "I may let you know what I find in it if you leave your address. Goodbye!"

Tom waved his hand, gave orders to close the hatches and submerge the M. N. 1, and a few moments later the sea closed over her, leaving the other vessel to grapple uselessly for the treasure-ship.

"What are you going to do, Tom?" asked Ned of his chum, as they were all gathered in the main cabin half an hour later.

"Head for home as soon as we can. I've had enough of this, and I want to get at something else I have in mind. But first I'm going to see what's in this box."

It required the strength of Koku to open the small steel box, but when it was torn apart, for the combination was impossible to guess at, all that was seen were bundles of papers. The case having been hermetically closed, no water had penetrated it, though it had been submerged a long time.

"What are they?" asked Ned of his chum.

Tom did not answer for a moment. Then having quickly examined the papers, he cried:

"We've struck it!"

"What?" they all wanted to know.

"The very thing Hardley was after. These are the missing papers in the oil-well deal--the papers that prove Barton Keith has a half share in property worth many millions of dollars. It was these papers that Hardley was after. He may have thought he could get the gold, too, but he wanted most these oil shares. Boys, we've found the fortune anyhow, in spite of the fellows who looted the gold boxes!"

There was no doubt about it. There were all the papers--the certificates of shares, the partnership agreement and other documents--to show that Mary's uncle was a rich man. The wreck of the Pandora held a fortune after all.

"How do you account for Hardleys acts?" asked Ned of his chum.

"Well, there are several explanations. I think we may be certain that he knew these papers were aboard the Pandora, for he must have intrusted them to the purser himself when he made a trip on the ship. When she sank he had not time to get them to take with him."

"He either knew then, or found out later, that the vessel carried, or was supposed to carry, a large amount of gold. He may have been honestly mistaken in thinking it was two millions. In any case he was playing safe, for he only promised me half if the treasure was found. He could have claimed this box as his property, and that is probably what he was after from the beginning. He was using me as a cat's paw, so to speak."

"Well, you beat him to it," observed Ned.

"Bless my necktie, I should say so!" agreed Mr. Damon. "Do you think he really expected to find the gold?"

"Either that or the papers," was Tom's answer. "He must have engaged the vessel and the grappling apparatus, and, possibly, a diver, after we set him ashore at St. Thomas. Well, we'll leave him to his own fun."

The M. N. 1 made good time back to her home port, nothing except a terrific storm occurring to mark the voyage. And as she submerged when that was on she did not feel it. After greeting his father, Tom lost little time in going to Mary's house with the box of securities and other papers.

"I want you to hand these to your uncle with my compliments," he said. "I've got the Air Scout out in the meadow. We'll go over in that. How is Mr. Keith?"

"Not very well," Mary answered, after she had got over her surprise at seeing Tom. "But this good news will restore him, I think."

And it certainly was a great tonic. Mr. Keith could hardly believe the story that Mary and Tom jointly told him. But at length he grasped the idea that he was a wealthy man again, and he exclaimed:

"Tom Swift, I'm going to share half with you!"

"Oh, no," retorted the young inventor. "I couldn't think of that. If you want to pay part of the expenses of the trip I shan't object to that, as I intend giving the gold I recovered to Mr. Damon. But as for taking any of the oil shares--"

"Then, Mary, you shall take half!" exclaimed Mr. Keith. "I have more money now than I'll ever spend. Mary, half of it is yours, and if you don't let Tom Swift have a say in the spending of it-- Say, Mary, have you thanked him yet?" he asked with a twinkle of his eyes. "Well, Uncle Barton, I--I don't know--"

"Then do it now!" cried her uncle. "Tom, if you could have any reward you wanted, what would it be?"

Tom took Mary in his arms and--But I refuse to betray any secrets. Anyhow, some time later when Ned asked his chum if he felt entirely satisfied with the result of his undersea search, the young inventor replied: "I certainly do!"

Tom admitted to his father that a mistake had been made in not installing the gyroscope rudder. There was no excuse for not taking it. Tom declared, as it was small and took up little room, and it might have saved them from what was a close call at one time.

"I'll take it on my next submarine trip," the young inventor promised.

Ned wanted to bring suit against Hardley to recover half the expenses of the trip, but Tom would not consent to it. After all, the value of the oil well property was more than the gold the Pandora was reputed to have carried. No attempt was made to take from Tom the comparatively small amount he had salvaged. Perhaps whoever had put it on board did not want to admit the trick that had been played in filling the boxes with iron disks.

Dixwell Hardley made no further trouble. He could not, for he was so entirely in the wrong. He sold out his shares in the oil property, and a company took possession which gave fair treatment to Mary's uncle.

And this is the end of the story. But the future holds further adventures for Tom Swift which, let it be hoped, he will see fit to order recorded.