In this case their fate was certainly sealed.

Lost at the bottom of the sea; lost in the great Atlantic Valley. What an awful thing to consider!

Frank knew, however, that they could stay death for a number of days.

There was enough material in the generators to keep them alive that length of time.

But if the Dart should not return in that interval they were truly lost.

It was some while before any one ventured to speak again.

Then Bell said, despairingly:

“How far is it to the land?”

“Fully a thousand miles in any direction,” replied Frank.

“We can hardly walk then?”

“No, I think not.”

“Is there any possibility of the Dart returning?”

“We can only hope that it will. Our only way is to wait here.”

Von Bulow sat down upon the rail of the sunken vessel, Captain Bell paced the deck, Frank tried to pierce the gloom of the ocean depths for some sign of the Dart.

And now, at this critical moment, a new and thrilling peril confronted the trio.

Suddenly Frank saw a long, sinuous body flash through the water some fifty feet distant.

He saw its outlines and its shining silver scales, and at once recognized a deadly foe.

“A swordfish,” he muttered.

Then he made a motion of warning to the others.

They leaped out of the way, but were not a moment too soon.

The huge fish, with its keen lance of sharpest bone, had made a dive for them.

As it dodged past him Frank struck at it with his ax.

The blow nearly severed one of the fins of the huge fish and a cloud of blood spurted into the water.

But instantly the swordfish turned and came again to the attack.

And now the critical moment had come. In those depths the swordfish was a fearful foe.

If he should strike any one of the party with his lance, it would mean instant death.

The monster seemed savagely aggressive as well.

On it came again at fearful speed and accuracy straight at Frank Reade, Jr.

The young inventor waited until the fish had almost reached him; then quick as a flash he dodged under it.

And as he did so he threw up his right hand, clutching the knife with the point upward.

By the sheerest of good luck the knife struck the fish and ripped his abdomen open to a great length.

This settled the contest. The fish’s entrails dropped out, and the monster lay upon the deck of the ship dead.

But this did not by any means dispose of the fearful peril which surrounded the divers.

A literal school of swordfish were seen bearing down upon the party.

It was useless to think of coping with them in such numbers. It was necessary to make quick and definite action.

Frank sprang toward the companionway and motioned the others to follow him.

They were not a moment too soon in this, as the fish came about in a cloud, hovering over the hatchway, and trying to force an entrance.

But the divers were safe for the nonce in their retreat, and it was deemed best to remain there until the fish should disperse.

But they seemed in no disposition to do this.

Indeed, they remained above the deck, besieging the party quite effectually.

The position was by no means a pleasant one.

“Well,” cried Frank, as they put their helmets together, “I don’t see but that we are obliged to stay here whether we will or no.”

“That’s so,” agreed Bill. “I wish the beastly critters would clear out.”

Von Bulow was getting depressed.

“The most of us better make our peace with the Almighty,” he declared. “We shall never get out of this scrape.”

And there the three divers were held imprisoned in the cabin of the sunken ship, while a rescue seemed indeed a hopeless thing.

But let us return to the Dart, and learn the fate which had overtaken it.

Barney and Pomp were faithful and reliable servants.

They were well familiar with the workings of the craft, and no ordinary accident would have troubled them long.

But the accident which befell the Dart was not an ordinary one.

Left aboard the boat, Barney and Pomp fell to skylarking.

They were as full of fun as a nut is of meat.

After jibing each other for a while they got to wrestling.

“Hi, dar, chile, don’ yo’ put yo’ han’s on me!” cried Pomp, as Barney closed with him. “If yo’ does yo’ shuah nuff get de wuss ob it!”

“Begorra, I’ll have the best av yez or me name’s not O’Shea!” cried Barney, hilariously. “Shure, I’ll niver be downed by a naygur!”

“Clar away dar, I’ish!”

But Barney was in for a ruction.

“Whurroo!” he cried. “Here’s at yez!”

Then they went madly whirling about the cabin in a lively tussle.

It was hard to say which had the best of it.

It was certainly a lively contest, and honors were even until suddenly Barney tripped over a rug.

Then down went Pomp’s head, and plump into the Celt’s stomach it went.

Barney went down, and Pomp was on top of him. The darky hung to his man like a leech.

“Ki, dar! Yo’ am not in it wif dis chile!” he shrieked. “Yo’ am beat, I’ish!”

“Divil a bit!” screeched Barney. “I’ll have yez off yet!”

But just at that moment something happened which terminated the friendly wrestle almost instantly.

There was a sudden severe shock, and the two jokers were thrown half-way across the cabin.

When they picked themselves up, both were dumbfounded to hear the electrical machinery buzzing furiously.

The submarine boat was swaying madly, and they had hard work to keep their feet, so violent was the motion.

“Massy Lordy!” gasped Pomp; “wha’ am de mattah, chile?”

“Matther!” ejaculated Barney. “Shure, the divil is carrying us away.”

“I don’ fink dat am jes’ a fac’!”

Barney sprang into the pilot-house instantly.

He tried to press the lever which shut off the speed current. It would not answer to his touch.

The submarine boat was shooting like lightning through the water.

How far they had run from the sunken wreck neither knew, but it was very likely several miles.

Here was a fearful situation.

The two looked at each other aghast. What was to be done? The risk was something awful.

The Dart was not far from the bottom of the ocean.

At any moment she might strike some projecting hillock or eminence. It would mean utter destruction.

Barney was pale as a ghost, and Pomp’s eyes bulged like moons.

“Golly, fo’ massy sakes!” wailed the affrighted darky. “We am done fo’!”

“Begorra, it’s kilt we’ll be if we don’t sthop the boat!”

“An’ Marse Frank am lef’ all alone behind dar. Mebbe we kain’t nebber find him no mo’.”

It was a horrible thought which oppressed the two jokers. But they were not the kind to remain inactive.

Something must be done.

Barney realized this. If the machinery was out of order the cause must be found and remedied.

He rushed down into the engine-room and began to examine it.

At once he saw the trouble.

One of the heavy dynamos had become unshelved, and the lever wire was twisted and broken.

Barney instantly shouted:

“Come down here, naygur!”

Pomp at once responded.

With their united effort the dynamo was relocated and the lever wire connected. Then Barney operated the lever and it worked all right.

The boat came to a stop.

And not a moment too soon. Just ahead was a mighty eminence, and the Dart would certainly have struck it at full speed.

“Golly!” gasped Pomp. “Dat am jes’ de berry closest call I ebber knowed ob!”

“Begorra, a miss is as good as a mile,” said Barney. “Shure, we must go back now.”

“Does yo’ fink yo’ kin fin’ yo’ way back, chile?”

This was quite a problem. The Dart had undoubtedly run many miles, and to find the way back, as no note had been taken of their course was all a matter of chance.

“But fo’ de Lor’ sakes, whatebber struck the boat in de fust place?” asked Pomp. “Howebber did it git started?”

“I’ll show yez,” said Barney.

He led the way to the pilot-house.

Upon the vessel’s bow was a huge specimen of fish. It was a swordfish.

The monster had dashed against the vessel with such force that a part of the bulwark had been carried away, and the swordfish had been caught in the wire hamper of the rail.

It was certainly the shock given the vessel by the huge fish which had dislocated the dynamo and disarranged the mechanism of the Dart.

As the heavy body of the fish sagged the boat, Barney donned a diving suit, and going out, cut away the incumbrance.

The damage was repaired as much as possible, and then the boat was turned about.

The return course, as nearly as could be guessed, was taken.

The Dart sailed on rapidly. But though miles were passed, not sign of the sunken wreck was seen.

Barney doubled back on his course and sailed for miles. Hours passed and the anxious searchers were unrewarded.

“Massy sakes!” gasped Pomp. “I done fear dat Marse Frank am done fo’ dis time. I jes’ fink he nebber come back no mo’!”

“Begorra, he was a good, kind masther!”

“Dat am so, honey!”

“On me worrud, I’ll niver give up looking for him if I have to sail through these seas fer all me loife!”

“I’m wid yo’, I’ish!”

So they kept sailing about at random for a full day.

Then Barney suddenly cried:

“Look yonder, naygur. Phwat do yez call that?”

It was a little star of light twinkling through the gloom. There was but one explanation for its presence in those depths.

It was an electric light, and doubtless came from the helmet lamp of one of the lost divers.

Barney at once shaped the course of the Dart for it. The two jokers anxiously awaited the result.