"Hello, Tom Swift! Hello, Ned! Glad to see you both! Busy, as usual, I'll wager. Bless my check book! I never saw you when you weren't busy at some scheme or other, Tom, my boy. But I won't take up much of your time. Tom Swift, let me introduce my friend, Mr. Dixwell Hardley. Mr. Hardley, shake hands with Tom Swift, one of the youngest, and yet one of the greatest, inventors in the world! I've told you a little about him, but it would take me all day to tell you what he really has done and--"

"Hold on, Mr. Damon!" laughed Tom, as he shook hands with the man whom Mr. Damon had named Dixwell Hardley. "Hold on, if you please. There's a limit to it, you know, and already you've said enough about me to--"

"Bless my ink bottle, Tom, I haven't said half enough!" interrupted the little, eccentric man. "Wait until you hear what he has done, Mr. Hardley. Then, if you don't say he's the very chap for your wonderful scheme, I'm mighty much mistaken! And shake hands with Ned Newton, too. He's Tom's financial manager, and of course he'll have something to say. Though when he hears how you are going to turn over a couple of million dollars or more, why, I know he'll be on our side."

Ned's eyes sparkled at the mention of the money. In truth he dealt in dollars and cents for the benefit of Tom Swift. Ned shook hands with Mr. Hardley and Tom motioned Mr. Damon and his friend to chairs.

"Now, Tom," went on the strange little man, "I know you're busy. Bless my adding machine, I never saw you when--"

At that moment there arose in the corridor outside Tom's private office a discord of voices, in which one could be heard exclaiming:

"Now yo' clear out oh heah! Massa Tom done tole me to sweep dish yeah place, an' ef yo' doan let me alone, why--why--"

"Huh! Radicate him big stiff--dat's what! Big stiff! Too stiff for sweep Master's floor. Koku sweep one hand!"

"Oh, yo' t'ink 'case yo' is sich a big giant, yo' kin git de best ob ole black Rad! But I'll show yo' dat--"

"Excuse me a moment," said Tom, with a smile to his guests as he arose. "Eradicate and Koku are at it again, I'm sorry to say. I'll have to go out and arbitrate the strike," and he left the room.

While he is settling the differences between his faithful old black servant and Koku, the giant, I will take the opportunity of telling my new readers something about Tom Swift.

Those who are familiar with the previous books of this series may skip this part. But it will give my new audience a better insight into this story if they will bear with me a moment and peruse these few lines.

As related in the first book, "Tom Swift and His Motor Cycle," the hero seemed born an inventive genius. It was this inventive faculty which enabled him to take the motor cycle that tried to climb a tree with Mr. Wakefield Damon on it and make the wreck into a serviceable bit of mechanism. Thus Tom became acquainted with Mr. Damon, who among other eccentricities, was always "blessing" something personal.

Tom Swift lived in the city of Shopton with his father and their faithful housekeeper, Mrs. Baggert. It was so named because the Swift shops were an important industry there. Tom's father, as well as Tom himself, was an inventor of note, and employed many men in building machines of various kinds. During the Great War the services of Tom and his father had been dedicated to the government.

There are a number of books dealing with Tom's activities, the list of titles of which may be found at the beginning of this volume.

Sufficient to say here, that Tom invented and operated motor boats, airships, and submarines. In addition he traveled on many expeditions with Mr. Damon, Ned, and others. He went among the diamond makers and it was when he escaped from captivity that he managed to bring away Koku, the giant, with him. Since then Koku and Eradicate Sampson, the faithful colored man, had periodic quarrels as to who should serve the young inventor.

Besides inventing and using many machines of motive power, Tom Swift engaged in other industries. He helped dig a big tunnel, he constructed a photo-telephone, a great searchlight and a monster cannon. Occasionally he had searched for treasure, once under the sea, with considerable success.

Of late his and his father's industries had become so important that a number of new buildings had been constructed and the plant greatly enlarged. Ned Newton, who had once worked in a Shopton bank, became financial manager for Tom and his father, and plenty of work he found with which to occupy himself.

Just prior to the opening of this story Tom had perfected a noiseless aeroplane--or one so nearly silent as to justify the name. The details of it will be found in the book called "Tom Swift and His Air Scout." In this mechanism of the air Tom had had some wonderful experiences, and they had not been at home more than a few weeks when New Newton broached the subject of undersea wealth.

The talk of Tom and his financial manager was interrupted by the arrival of Mr. Damon and the stranger he had introduced as Mr. Hardley.

Eradicate, or "Rad," and Koku, have been mentioned. Rad was an ancient colored man who once owned a mule named Boomerang. Sampson was the colored servant's last name, and he declared he had chosen the one "Eradicate" because in his younger days he was a great cleaner and whitewasher, "eradicating" the dirt, so to speak.

Boomerang had, some time since, gone where all good mules go, though Eradicate declared he would get another and call him Boomerang II. But, so far, he had not done so.

Rad, though too old to do heavy work, still believed he was indispensable to the welfare of Tom and his father; and as the giant Koku, who was physically an immense man, held the same view, it followed there were frequent clashes between the two, as on the occasion just mentioned.

"What was the matter, Tom?" asked Ned, when the young inventor came back into the room.

"Oh, the same old story," replied Tom. "Rad wanted to sweep the hall, and Koku insisted he was to do it."

"What'd you do, Tom?" asked Mr. Damon.

"I settled it by having Rad sweep this hall and sending Koku to do another--a bigger one I told him. He likes hard work, so he was pleased. Now we'll have it quiet for a little while. Did I understand you to say, Mr. Damon, that--er--Mr. Hardley I believe the name is--had a proposition to make to me

"That's exactly it, my dear Mr. Swift!" broke in the man in question. "I have a wonderful offer to make you, and I'm sure you will admit that it will be well worth your while to consider and accept it. There will be at least a million in it--"

"Bless my check book, I thought you said several millions!" exclaimed Mr. Damon.

"So I did," was the rather nettled answer. "I was about to say, Mr. Damon, that there will be at least a million in it for Mr. Swift, and another million for myself. There may be more, but I want to be conservative."

"Talking in millions, and calling himself conservative," mused Ned Newton. "Somehow or other I don't just cotton to this fellow!"

"When our mutual friend, Mr. Damon, told me about you, my dear Mr. Swift," went on Mr. Hardley, "I at once came to the conclusion that you were the very man I wanted to do business with. I'm sure it will be to our mutual advantage."

Tom Swift said nothing. He was willing to let the other talk, while he waited to see how far he would go. And, as Tom said afterward, he, as had Ned, took an instinctive dislike to Mr. Hardley. He could not say definitely what it was, but that was his feeling. That he might be mistaken, he admitted frankly. Time alone could tell.

"Have you a half hour to give me while it explain matters?" asked Mr. Hardley. "I may go farther and say I need considerable time to go into all the details. May I speak now?"

To tell the truth Tom Swift had many important matters to consider, and, in addition, Ned Newton was prepared to go over some financial ends of the business with Tom. But the young inventor felt that, in justice to his friend Mr. Damon, who had brought Mr. Hardley, he could do no less than give the stranger a hearing. But only the introduction by Mr. Damon brought this about.

"I shall be glad to hear what you have to say, Mr. Hardley," said Tom, as courteously as he could. "I will not go so far as to say that my time is unlimited, but I will listen to you now if you care to go into details."

"That's good!" exclaimed the visitor. "I'm sure that when you have listened you will agree with me."

"He's a little bit too sure!" mused Ned.

"Bless my pocketbook, Tom, but there are millions in it!" exclaimed Mr. Damon. "Literally millions, Tom!"

Mr. Hardley settled himself comfortably in his chair and looked from Tom to Ned.

"May I speak freely here?" he asked, with obvious intent.

"You may," the young inventor answered. "Mr. Newton is my financial manager, and I do nothing of importance without consulting him. You may regard him as a member of the firm, in fact, as he does own some stock. My father is practically retired, and I do not trouble him with unimportant details. So Mr. Newton and I are prepared to listen to you."

"Very well, Mr. Swift, I'm going to ask you a question. Have you all the money you want?"

Tom laughed.

"I suppose any man would answer that question in the negative," he replied. "Frankly, I could use more money, though I am not poor."

"So I have heard. Well, would a million dollars clear profit appeal to you?"

"It certainly would," was the answer.

"Then I am prepared to offer you that sum," went on Mr. Hardley. "But there are certain conditions, and I may say that this vast wealth is not easy to come at. However, with your inventive genius, I am sure you will be able to solve the mystery of the sea. Now then as to details. There lies, on the floor of the ocean--"

"Hark!" exclaimed Tom, raising a hand to enjoin silence. "I think I hear some one coming." At that moment there was a knock at the door.