Turningto Darrin the Englishman held out his hand.
"Good-bye" he said, simply. "You have been a good comrade. I trust you have not been disappointed in us, either."
"Let's not say good-bye yet," urged Dave cheerfully. "Surely we are not going to give up and drown, merely because a lot of German rascals so will it."
"But we cannot last long in the water," protested the Englishman, mildly.
"At least, sir," Dave suggested, "we shall not die until we have to. You swim?"
"Once I did."
"Then you can swim now. The sea is nearly smooth. Let us try to keep together. And you, Captain Kennor? You swim?"
"Yes."
"Good. We'll keep together as long as we can."
At this moment the Englishwoman, the shortest of the quartette, gave a little cry as she found her footing giving way beneath her.
"All together!" cried Darrin, with a cheeriness he did not feel, as he gripped the woman's left arm.
Another drop of the deck sent them all adrift. The Englishman supported his wife on her right. Captain Kennor, nearly silent, but undaunted, swam slightly behind the others that he might offer aid wherever needed.
Strangely enough, though the swimmers spoke to each other occasionally, none now referred to the dastardly conduct of the enemy in setting them thus adrift to drown.
"You are cold, my dear, I know," said the Englishman to his wife. "Are you suffering otherwise?"
"No; but though I would not willingly drown myself, I shall not be sorry when we give up and go down."
"Had I felt that way the last time I found myself in the water," spoke up Dave, "I would not be here now."
"You had on a life belt. Now none of us has," answered the Englishwoman, her teeth chattering. "We cannot last long."
"After my last experience, madam," Dave assured her, "I shall never dare say that as long as life lasts."
"Why not face facts calmly?" she asked. "Probably I shall last a quarter of an hour beforeI die of cold. I may survive for twenty minutes or a little longer. You are strong, and may keep up for an hour or more. What can possibly come to our aid in that short time?"
"Who can say?" was Dave's counter-question.
For some time, they swam in silence. They did not attempt to make progress. Motion enough to keep afloat was all that was called for.
All at once Dave wondered whether his eyes were playing him tricks, or whether he really saw the top of a conning tower approaching him. It was not likely that the enemy would remain about, and come back to see how it fared with the victims of their cruelty.
Then the something in the water took on another vague shape. Darrin shook his head in an effort to get the water out of his eyes. He peered again. The shape, whatever it was, and if it really existed, was beginning to get on his nerves. It seemed to come nearer.
"Captain Kennor!" called Darrin, sharply.
"Aye!" responded the Dane.
"Are you still swimming strongly?"
"Aye!"
"Then will you swim ahead and see what it is that my eyes show me on the water?"
"Oh, aye!"
With lusty strokes the Dane swam around him, and then ahead.
"A little more to the left!" called Dave.
Then Captain Kennor believed that he saw it, too, and headed straight for the object. Getting nearer he sent back a real cheer.
"What is it?" Darrin called.
"A spar!"
"Any size?"
"Large enough us to hold all up! Swim dis vay! Alone, can I hardly push it to you."
Neither Dave nor the Englishman needed urging. They swam, still bearing the woman between them. The sight of the Dane ahead of them holding to the spar with one arm, and holding up the other hand, heartened them wonderfully.
Soon all three had gained the spar, and Captain Kennor, drawing a cord from his pocket, soon succeeded in lashing the Englishwoman so securely to the spar that she could not slip away and perish.
"Now, you will remember what I said about not giving up," Dave reminded his companions.
"Why, yes, I am buoyed up, and perhaps you men can manage to hold on, also," admitted the woman. "Yet we must freeze to death."
"We will still dare to hope," Darrin replied, calmly.
"You are a splendid inspiration, Mr. Darrin!" declared the Englishman, heartily. "I wish I could believe that you are a true prophet, as well."
"Oh, well," spoke Dave, with a lightness that was deceptive, "I've really been in several worse scrapes than the present one."
But to himself he added:
"May I be forgiven for uttering what seems to me to be a possibly helpful lie!"
Though they were now safely afloat for some time to come, their situation rapidly became worse, owing to the increasing cold. Especially was this noticeable in the case of the Englishwoman.
From time to time her eyes closed. When spoken to she had to exert considerable effort to shake off her languor before she could reply. She became still more drowsy; evidently she was on the verge of freezing to death. From speaking kindly her husband dropped into sharp tones for the sole purpose of keeping her awake. Presently he was forced to resort to light blows in order to bully her into wakefulness. Once she fell soundly asleep she would not again awake.
As for Captain Kennor, he held on almost dumbly. He seldom spoke, his eyes mournfully regarding the woman whose battle for life was slowly being lost.
"This is awful!" cried the Englishman, hoarsely, after another effort to rouse his wife from slumber.
"For all of us," Darrin admitted, "though there is still hope."
"Where?" inquired Captain Kennor.
"I do not know," Dave confessed. "Yes, I do, too, though! Look yonder! No, in that direction!"
At first the others could not make it out. Captain Kennor was the first to see what Dave had found. It was only a low, dark cloud on the horizon, and it looked as though smaller clouds detached themselves and sailed away on the low-hanging sky.
"I see it, too!" cried the Englishman, at last. "But what is it?"
"A ship," Dave answered. "To be more exact, it looks like a destroyer, and it looks too as though it might pass within a quarter of a mile of us."
"Look, my dear—look!" the Englishman urged his wife, shaking her in his eagerness to have her realize the thread of hope that dangled before their eyes. "A ship coming! We are to be saved."
Her eyes opened at last; the woman struggled bravely to show interest in the sight that half-cheered the others, but she could not. She was too far gone, and her eyes closed again.
"Keep your wife awake, sir, if you have to begin to pull her hair from her head!!" It was a command. "See how near that craft is getting. Jove, sir! I believe it is one of our own Yankee ships!"
"But they will not come close enough to see us," objected Captain Kennor, with the practiced eyes of the veteran seaman. "They are not using their searchlight, and we have no way of signalling to them."
Without speaking Darrin tried a desperate hope. In one of his hands something gleamed out into the night.
"What is it?" demanded the Dane. "Himmel! Der flashlight! Vere or ven did you by dat come?"
"I found it in the locker of our sleeping cabin, and hid it in my clothes," Dave answered, as he again tested the light. "I did not want to speak of it unless there should come some hope to us. This light was evidently left by some German who had used that cabin. It's waterproof, too. When I found it I had a hope that it might come in handy before I got through with this adventure. And now!"
Waiting only a minute or two longer, Dave, clinging to the spar with one arm, held the other hand as high aloft as he could.
"Help!" he signalled by flashes in the Morse code. "Help!"
"It is such a tiny glow, to carry so far!" sighed the Englishman.
"Maybe id vill seen be," said Captain Kennor.
Dave continued to signal until, to his great joy,there came an answering signal from a blinker light which asked:
"Who are you?"
"Four castaways, clinging to a spar. Help before we freeze!" Dave flashed back, desperately.
"If only the commander of that boat does not suspect us of being a German submarine springing a trap!" cried the Englishwoman.
A searchlight flashed up, then its broad beam stretched across the waters as the operator tried to pick up the floating ones.
Dave threw the flash into a continuous light while the searchlight beam continued groping. Then, in a blessed instant, the beam struck almost blindingly across the spar and the four human beings held up by it.
"Now, they've spotted us," Dave cried, exultingly. "They won't run away and leave us without a look-in."
Holding the spar with the searchlight beam, the destroyer changed its course, bearing down rapidly upon them. Then it stopped and a motor launch was lowered from davits.
With a burst of speed the launch came alongside the spar. Busy hands were outstretched. The Englishwoman was the first to be taken aboard, after a few quick slashes had freed her from the binding cord.
"Why, here's Lieutenant Commander Darrin!"
"Help!"
"Help!"
exclaimed a voice. Dave, almost too weak to speak, was hustled into the boat, then the other two men were taken over.
Blankets were wrapped about the rescued ones, and the launch dashed back to her ship.
"A woman, Lieutenant Commander Darrin and two other men!" the officer in charge of the launch hailed the destroyer.
"Darrin!" cried a voice. There was even greater bustle at the top of the gangway that had been lowered as the launch ran alongside. As swiftly as possible the four rescued ones were rushed up the side.
"Old Darry himself, eh?" cried a joyous voice, as Danny Grin hurried up. "Has the woman any relative in the party?"
"Yes; her husband," Dave answered weakly, then collapsed.
"Take the woman and her husband to my quarters," Dalzell directed. "Have a cot put in and lashed for the husband, and put the woman in the berth. Mr. Darrin and the other man will go to the sick bay."
Willing hands bore the rescued ones as ordered. Dan himself followed Dave's bearers down to the sick bay and there supervised the treatment given Dave and Captain Kennor, while the medical officer went to Dan's quarters, the best on the craft.
The Englishman was soon more comfortable. His wife, however, required serious attention. Dalzell shook his head over Dave, who appeared all in and not able to talk.
"Was he in the water longer than the rest of you?" asked Dalzell, as soon as Captain Kennor was able to talk.
"No; but he vas der water in vonce before," was the reply. "Der second time he could stand not so well."
That gave Dan the clue. As soon as the medical officer could be spared from the care of the Englishwoman for a few moments he was ordered to the sick bay.
"Mr. Darrin may pull through, but I won't guarantee anything," said the surgeon, after an examination. "The chances are all against him. I am afraid the woman is going to die also."
Thatdouble report helped Dan Dalzell to make up his mind.
"Run straight for port," he ordered the executive officer, naming the nearest British haven that offered rail connection.
In an hour and a half the destroyer had dropped anchor at the port.
More medical aid was brought aboard, including a trained nurse for the Englishwoman.
A few hours after daylight the woman had recovered sufficiently to warrant her removal to a hospital on shore. No strong hopes were yet entertained of keeping her alive for more than a day or two. Her husband had stood the watery ordeal much better.
Captain Kennor, who, with Dave, was taken to the hospital later in the day, had nearly recovered by the day following.
But for Dave Darrin there followed black hours. According to the doctors a severe case of pneumonia was about the best that could be predicted for him.
On the day after he was taken ashore Darrin opened his eyes with a light of recognition in them. At the foot of the cot, in a chair, sat a stalwart, youthful figure. Dan Dalzell, whose orders took him to sea again that night, was waiting to the last for better news.
"Dan," Dave called, softly, and Dalzell was instantly bending over him.
"David, little giant, did you know that the 'Reed' had the good luck to pick you up?" asked Dan, eagerly.
"I had a notion of it, but I was too dazed to know really," Darrin answered.
"I've been here about all the time ever since," Dan went on. "I wanted to know the news of you as soon as it could be had. But you're going to be all right, now."
"Of course I am," agreed Dave, feebly.
Unseen by the man on the hospital cot, Dan signalled with one hand. Down the ward came a doctor, followed by a young woman wearing the blue cape ulster of the Red Cross. There was a quick, glad cry; soft lips touched Dave's face.
"Belle!" gasped Dave, delightedly.
"I'm going to be allowed to sit by you quite a bit, dear, if you don't try to talk to me," replied the steady voice of Belle Darrin. Summoned by cable sent by Dan, Belle had journeyed swiftly from France.
"And now I'm off and back to my ship, Belle," said Dan. "But I know you'll find a way to get a radio message through to me when Dave is improved enough to warrant it. Good-bye, Darry, old chap!"
And Dan was off, not because he didn't want to stay, but because he knew his chum would want to see the most of Belle. As for that young woman, who held none too positive hopes of Darrin's recovery after what the doctors had told her, she forced herself to be calm and smiling and sat close by, her hand on Dave's forehead when he dropped off into a feverish, troubled sleep.
The next day Belle chatted with her husband a little, in a cool, steady voice. Two days after that Dave was actually permitted to sit up.
On the sixth day after he had been taken to the hospital Dave was mending so rapidly that Belle, who was obliged to leave that afternoon for her Red Cross post in France, felt wholly easy in mind as to his condition.
"It was a lucky chain of events, my two swims in the channel," Darrin told her before they parted.
"Lucky, when the experience nearly cost you your life?" exclaimed Belle.
"It gave you an excuse for coming to me, and gave me the time and leisure to be with you."
"Dave Darrin, you don't mean any such thing!You are needed aboard your ship, and I am needed for my work in France, and nothing can be called really good luck that takes either of us away from his post of duty in war-time."
"You little patriot!" Dave laughed, jestingly.
"You believe it just as much as I do," Belle maintained stoutly. "I'm glad to have been here with you, dear, but I shall be glad to find myself back at my post. And you know you are glad that you will return to your ship tomorrow."
"If she comes in," Darrin amended.
"Dave, aren't you nearly wild to get back to duty?" she persisted.
"Yes, I am, for as you say, dear, we are all needed at the posts assigned to us. There is another reason why I must get back. The work that has been cut out for us is not proceeding as it should. We have made some good 'catches' in the way of mines, yet the fact is that mines are being planted much faster than we have been taking them up. I must get back to duty and see if I can find out what is wrong."
Buttoning his overcoat tightly Dave Darrin walked with Belle to the railway station. The train left so soon after their arrival that there were not many moments left the young couple for leave-taking. After the train had started Dave watched it out of sight. There had been something uncomfortable in his throat, but as heturned away the lump vanished and his jaws set squarely.
"Now, my work is cut out for me," he told himself. "I can do only one man's part in this war, but I must do that to the limit and try to make the world a safe place of residence for that little woman and all others like her!"
No sooner was the "Grigsby" in port, the next forenoon, than Lieutenant Fernald came ashore and straight to the hospital.
"Going on board today, sir?" was Fernald's greeting.
"You couldn't keep me ashore any longer," Darrin declared.
"Good enough!" said the executive officer, heartily. "We need you, sir! We've been doing our best, but the enemy has been gaining on us. Last night two ships struck mines and went down before rescue could reach them. The Germans are beating us at this mine game, and something must be done, which, of course, sir, is another way of saying that a way must be found to do the right and necessary thing."
"I've been thinking that over for twenty-four hours," Darrin went on. "As soon as we are aboard I want to talk the whole situation over with you. Will Dalzell be in today?"
"In about an hour, sir, I think. He needs fuel and some food supplies."
"Then we'll hold a council of war in the chart-room," Dave decided, as he buttoned up his coat. "I'm ready, Fernald."
Dave had already thanked the hospital authorities, and taken leave of them, so the two young naval officers passed outside, made their way down to the water front, and soon thereafter stepped aboard the "Grigsby," reporting their arrival on board to the watch officer. Dave also saw that the forward gun damaged in the fight with the German destroyers had been replaced by a new one. From the gangway they went direct to the chart-room.
"I'll hear the reports on the work now, Fernald," Dave announced.
Two of the papers that came under Dave's hand especially interested him. One was a detailed list of the ships that had struck mines during the last week in the waters in which he and Dalzell had been operating. The other document contained a report on the discovery and sinking of one fighting submarine and one submarine mine-layer.
From these reports Dave turned to the charts of the local waters. When Fernald came back with Dan Dalzell, Dave was still poring over the charts.
"From the rapid way in which German mines are being planted in these waters," Dave told hisbrother officers, "I am satisfied that the enemy submarines do not usually go all the way back to the base port. I believe that the mine-layers are often met by other craft that supply them with mines, and that the submarine mine-layers return quickly to the job of planting mines. Now, the sea area in which the mines are planted leads me to feel certain that the mine-layers rest frequently on these three shoals."
Dave pointed on the chart to the shoals in question.
"How many mine-sweeping craft have we now under our orders?" he inquired.
"Nine," said Dan, promptly.
"How many of them can we spare from mine-sweeping?"
"None," Dalzell replied, positively.
"Either we must spare some, or we must have some sweeper craft added to our fleet," Dave went on. "There are three of these shoals, and hereafter I want two mine-sweepers to spend their time dragging their wires over each shoal. That will take six craft, and these will not have time to do any sweeping in the open sea. We cannot clean up the mines themselves with three craft, can we?"
"Plainly not," Dan agreed, "since, with all nine, we have not been able to find and take up all the mines we should have located."
"Then we shall have to have more craft," Dave nodded. "Yet if we cannot have more craft assigned to this work, we must go ahead with what we have and do more work. But I believe that the hunt over the shoals should be kept up day and night, without rest, for I am satisfied that the enemy mine-layers rest on these shoals more frequently than we have supposed."
After some further conversation Dave had his launch cleared away and went over to a British battleship for a conference with the British admiral in command in those waters. The best the admiral could do was to supply him with three of the hundred-and-ten-foot patrol boats. These, however, were provided with sweepers and possessed good speed.
"I hope you're right, Mr. Darrin," said the admiral, at the close of the interview. "To be frank with you, your predecessor in the work of cleaning up enemy mines in this area was a British naval officer, considerably older than yourself. He is a very capable man in many ways, but we felt that he had been so long on coast work that he was growing much too stale. So, when I decided to transfer him to other duties I thought of trying one of your American officers, a young man, full of spirit, and fresh for this work. So I asked your admiral for some one, and he sent Dalzell and yourself."
"So far," said Dave, "I have not done any better than my English predecessor, sir?"
"Frankly you have not, yet we must remember to deduct your very necessary week in hospital. However, you have done some other excellent things. The capture of the mine-laying neutral, the 'Olga,' for instance, was a splendid bit of work. The fight that you and Mr. Dalzell had with the three enemy destroyers was a fine job. But the mines in these waters continue to be as much of a menace as before."
"They won't be, by this time next week, sir. I promise that," said Dave, rising. "How soon can the commanders of the three patrol boats report to me?"
"At once. All three are here in the harbor, and, I am told, they are ready to put to sea."
"Then, sir, I propose, within a week, to hand you a wholly satisfactory report," Darrin went on. "I had to put in some time on the ground, and it was necessary to study a new problem. Then came a series of adventures that took me out of the work for a while. But now, sir, I hope to show you something new—results!"
Thethree shoals selected by Darrin extended over a length of about thirty miles along the coast. It was the center one of these shoals on which he had hadpreviousexperience.
Further, it was arranged that Dalzell should, in general, cruise along the lower fifteen miles of this stretch, while the "Grigsby" should cover the upper half. From time to time the two destroyers would meet.
After sending three mine-sweepers and the three patrol boats to the shoals, two craft to each shoal, Darrin saw to it that the other six were assigned to duty in the deeper waters off shore.
Then, with a hearty signal to the "Reed," the "Grigsby" started northward. She steamed by the southernmost shoal, and was passing the second when Darrin was called to the bridge by Ensign Ormsby.
"That patrol boat in there signals that she has made a find, sir, so I have changed the course and am heading in."
Dave's eyes gleamed as he made out the next signal from the patrol, which was:
"Soundings show her to be a big craft. Shall we rig the small bombs on the sweep wires?"
"Wait until we arrive," was the answering signal from the "Grigsby."
In a few minutes the destroyer was within hailing distance of the patrol boat, which was lying to in the neighborhood of the find.
"The enemy submarine appears to be at least 275 feet long, sir," reported the patrol boat commander.
"Then a depth bomb should do the business better," Dave shouted back through the megaphone. "Sail over the craft with your sweep, and I'll follow. Signal when you judge us to be squarely over her."
Under bare headway the "Grigsby" fell in behind the now slow-moving patrol boat. Almost at once the wire sweeps discovered the hull of the hiding monster.
Ahead steamed the patrol boat, the destroyer following. Aft two men stood by the depth bomb apparatus. Down came the white flag of the British signalman on the smaller craft.
Dave's hand rested on the telegraph lever to the engine-room. He signalled for full speed ahead, then at the proper moment he shouted:
"Let her go!"
An instant later the bomb splashed into the water.
Immediately following the splash there came a sullen, rending roar under water. A great column of water leaped up from the sea, a heavy volume of it landing on the after deck of the destroyer, all but washing overboard one of the lookouts. The pressure of water fairly lifted the stern of the "Grigsby" until her bow dipped far in.
Ensign Ormsby was thrown flat, almost rolling from the bridge. Dave, fortunately, had taken a grip that saved him from falling.
It seemed as though the destroyer herself had been blown up, but she quickly settled and scooted ahead at a furious rate.
"Half speed ahead," Darrin signalled, as soon as he could let go his grip, and the "Grigsby" slowed down. At the same time she swung around.
Even at that distance the huge spread of oil on the surface could be seen. A wild Yankee cheer rose, which was promptly echoed by the British tars of the patrol boat.
"No depth bomb ever made that upheaval," Dave gasped, as soon as he could speak, and Mr. Ormsby, much shaken, had picked himself up. "The bombs are ugly affairs, but that felt like the explosion of about ten of them."
"Did you notice, sir, that the explosion lasted more than twice as long as we've ever known one to last before?" the watch officer asked.
"Yes."
"Then what happened, sir?"
"Either our explosion touched off a torpedo, which does not seem likely, or else—"
For an instant what he was about to say sounded so absurd that Darrin hesitated.
"Well, sir—?" queried Ormsby.
"Or else that was a mine-layer, with a full cargo of mines aboard, all ready for business, and—But you'll think I've gone daffy."
"No, I won't, sir; not after the way this ship rose out of the water," the watch officer declared. "You mean, sir, that our bomb went off right over that craft's cargo of mines, and that the shock must have set off the mines."
"That's certainly the way it looks to me," Darrin nodded.
"I believe it, sir."
Just a few moments later the patrol boat came within hail. Through his megaphone Darrin stated what he believed had taken place.
"It's the only thing to account, sir, for such a tremendous explosion," replied the commander of the patrol. "I've been on hand to see a lot of depth bombs go off, and I never saw an upheaval like the one you produced, sir."
"Have soundings taken, Mr. Ormsby," Darrin directed. The depth of the water was quickly reported. Dave glanced at the sky.
"The light will be strong enough for anotherhour," he decided. "Have our two divers prepare to go down at once."
A launch, cleared away with the divers on board, was anchored in the middle of the oil spot. Two divers went over the side. Presently they signalled for extra cables. When these were let down they attached pieces of metal and gave the signal to haul away.
By the time that the hour was up Darrin had abundant evidence to prove that he had destroyed a mine-layer, and that his bomb had blown up several mines stored on the craft. This evidence took the form of fragments of mines.
"Some of these pieces must even have been driven up against our hull," Darrin declared. "It is a wonder that we were not sunk."
"The counter pressure of the water would lessen the force of these fragments, especially after they had been blown out through the shell of the submarine," Lieutenant Fernald argued. "But I agree with you, sir, that it's a wonder the 'Grigsby' suffered nothing worse than a shaking."
Other evidence, too, the divers sent up. The destroyed craft had surely been a mine-laying submarine. The divers measured the length of the wrecked hull, finding it to be close to three hundred feet. They reported, too, that scores of German dead lay in the wreckage.
For hours nothing more happened. Just beforeten o'clock that night the mine-sweeper's blinkers signalled a call to the "Grigsby," then about four miles distant.
"They've found something," Darrin chuckled, when he reached the bridge on a call from Lieutenant Fernald.
As the "Grigsby" was heading in toward the shoal, and had some minutes still to go, Darrin asked:
"Mr. Fernald, you had a second and even more thorough inspection of the hull made, as I directed?"
"Yes, sir; and found the hull so secure that I did not wake you to tell you, sir. There has been no strain of the plates sufficient to start any of them."
"I'm thankful to hear that," Darrin acknowledged. "Even with the big, elastic cushion of water between us and that awful explosion, it seems almost incredible that we did not wreck ourselves as well as the enemy."
"You've found another submarine?" Dave shouted through the megaphone, as he rang for slow speed and ran parallel with the waiting snub-nosed craft.
"We've found two somethings, sir," came back the reply. "They lie about four hundred feet apart and heading in the same direction. I can find them again, sir, but I didn't go back over them for fear they'd take the alarm and run for it."
"Perhaps they have," Darrin suggested.
"I've dropped small buoys, sir, and can lead you over them."
"Then do so, and travel at full speed. Be prepared to get out of our way if we come fast after dropping."
Even the two cool-headed sailors who stood by the depth bomb apparatus stiffened themselves as they found the "Grigsby" following in the wake of the mine-sweeper. The after lookouts lashed themselves fast against injury by any such surprise as that of the afternoon.
As the signal flashed from the mine-sweeper ahead Dave passed the order for the bomb instantly after ordering full speed.
There was an explosion, but an ordinary one, such as this crew of the destroyer was accustomed to.
At full speed, too, Dave tried for the second hidden enemy boat. There was barely time to have the second bomb in place when signal and order came.
Another terrific explosion, like that of the afternoon! It seemed as though the waters must divide! Yet the "Grigsby," moving fast all the time, felt the shock severely, but not like the one of the afternoon.
About the destroyer came, playing her searchlight on the waters. The tell-tale oil patches werethere, showing only too plainly that two submarine craft had been destroyed.
"Apparently one craft carried no mines, while the other was loaded with them," said Dave to his executive officer. "Fernald, I think I'm beginning to get an idea of the way the enemy are working their mine-laying game. If I'm right we'll make a record along this patch of shoals while the hunting lasts."
Patiently Fernald listened and waited, but did not speak. He hoped to hear what his chief's idea was, but it was not the executive officer's place to ask for it.
"I may even be able to figure out when the best time would be for hunting these lazy rascals resting on the bottom," Darrin continued.
Mr. Fernald began to show signs of a more active curiosity.
"But I won't say much about it," Darrin smiled, "until I've more data to work on and have proved some part of my theory."
Lieutenant Fernald looked so much like a man who wished to speak that Dave laughed.
"Out with it, Fernald," he urged good-humoredly. "You've an idea, too. You may tell me if you wish."
"Why, sir," replied the executive officer, "I've about concluded that the enemy mine-laying submarines do not go back to base port for moremines. They have some method for delivering them near here, and thus the mine-layers are able to keep more steadily at work."
"That fits in excellently with my idea," Darrin nodded.
"And that would account for the great numbers of mines that the enemy is able to lay hereabouts, and yet not have many of the craft caught by us," Lieutenant Fernald continued.
"Exactly," Dave agreed. "Moreover, the mine-layers take on their new supplies at night, and do their resting here at night, and get away from these shoals just before daylight."
"Of course," Fernald agreed. "If they rested here much in the daytime the aircraft would discover and destroy them."
"We'll both keep at work on our ideas, Fernald," Dave proposed. "Besides, we can take time to find facts to support our theories. Then we can get together and start in the biggest smashing of mine-laying craft on record."
Both paused in their talk to listen to the sudden boom of guns. Judged by the sound and the wind, the firing was some six miles away.
"Lookout there!" Darrin sang out. "Do you see anything?"
"Yes, sir," came the reply from aloft. "It must be the 'Reed,' sir. She must have gotten into something stiff, for she's moving shoreward at slowspeed and firing as fast as she can serve her guns. She's firing in shoreward, sir."
"Giveus a rocket signal if you need help," Dave signalled the attendant mine-sweeper.
Then to the officer of the watch:
"Give us full speed, and we'll run down to see if the 'Reed' has work enough for two of our kind."
A little further south he signalled same orders to the patrol boat that he had given to the mine-sweeper.
Then the "Grigsby" rushed onward as if she scented something of which she did not wish her crew to be deprived.
As soon as Darrin discovered that Dalzell was using his searchlight he ordered the "Grigsby's" also to be used. Over the waters the bar of light swept until it picked up a sight that made the officers on the bridge gasp for sheer astonishment.
Two submarines, some five hundred yards apart, lay on the surface of the sea.
Strangest part of all, neither craft was servingits guns. Why they neither fought nor dived puzzled the "Grigsby's" officers until the "Reed's" guns ceased firing and her blinkers signalled to Dave:
"Don't fire on them unless I do. They're helpless."
The "Reed," first to approach the submarines, steamed in between them. Then as the "Grigsby" raced up, she received this message from Dalzell:
"Wish you would take charge of the nearer submarine. I'll handle the other."
On both enemy craft, as seen under the searchlight, the German crews had come out on deck. It was clear that they wished to surrender without further loss of life.
So Dave ordered a launch cleared away, with a prize crew armed to the teeth, Ensign Andrews in command.
"You men get as far forward as possible," Andrews shouted to the huddled enemy. "Be careful not to have any weapons about you. We'll accept you as prisoners of war, but any attempt at treachery will be sternly punished!"
As he spoke the ensign rested one hand on the barrel of a machine gun in the launch's bow. Instantly the Germans began to move forward, only their four officers remaining near the conning tower.
"Stand by to catch a line and make fast," calledthe ensign, as the launch, under headway, lay in close.
Though they plainly understood, not one of the German officers made a move to catch a rope. Instead, one of them called to the huddled seamen, two of whom came back to take the line.
Making fast, Andrews stepped aboard, followed by some of his armed crew.
"You are the only officers of this craft?" Andrews demanded.
"Yes," sullenly replied the ober-lieutenant.
"Be good enough to hold up your hands while we search you."
Though their eyes flashed their rage, the German officers raised their hands while a petty officer "frisked" them one after the other.
"None of them armed, sir," was the report.
"Then into the launch with them. Next, order the seamen and engine-tenders aft and search them. The launch will carry about twenty prisoners on the first trip."
Soon the score of prisoners had been delivered aboard the "Grigsby." A second lot was sent over, after which Andrews decided that he could take charge of the remainder on their own craft. He now had force enough with him to keep this unarmed remainder in subjection.
Heading an armed party the ensign went below in the submarine to make an inspection. He hadalready noted a shell-hole through the hull which had made it impossible for this submarine to dive without drowning the crew. But he found other matters to interest him. This was a mine-layer craft, and at the present moment she had more than twenty mines on board.
One of Dalzell's junior officers, searching the other submarine, found her to be a mine-layer, too, but with only two mines on board. This second craft, also, had been pierced through the hull in such fashion that there had been no chance for her to escape by submerging.
On each craft forward a crane had been set up, and still stood. Dan Dalzell's report, when made, shed a good deal of light on German methods.
The "Reed" had been barely drifting when two submarines had come up within two miles of the destroyer. It was the noise of erecting the cranes that had warned Dalzell's watch officer of their presence there on the dark sea.
Suddenly, through night glasses, Dan, who had been called to the bridge, discovered what was taking place. On the quiet waters of this night the two craft had managed to get near enough to each other to attempt to transfer mines from one to the other.
Then it was that the "Reed" had opened fire with her guns, had turned on her searchlight and had rushed in.
As soon as the German commanders found their boats punctured into helplessness they had signalled their surrender.
"But I was glad indeed when I saw you bearing down on us," Dan announced, when he visited his chum a little later. "The enemy had surrendered, but I know enough of German treachery to realize that they might let me drive in close and then try to torpedo me. I needn't have worried, but of course I could not afford to take chances."
Sending for Boatswain's Mate Runkle, Dave inquired:
"Do you speak German?"
"I know about six words, sir; not as many as eight."
"Then you are the man for the job, Runkle. Go down among the prisoners that have been sent on board, the seamen, I mean, not the officers. Act as though you were there on duty, but not very busy. Use your six words of German and make English do for the rest. The German sailors won't understand you, unless some of them speak English. That will be all the better, for as soon as you discover that some of the men don't know what you are saying you will be able to judge which of those who speak no English are the most stupid, or the most likely to talk and tell us the truth. Spot three or four of these stupid ones, and then bring one of them here to the chart-room."
"Now, what on earth does the 'Old Man' want?" wondered Runkle, as he started away on this errand. "But never mind. Even if I can't guess what he wants it's a cinch that he knows. The stupidest one, eh? I wonder why any Fritz wouldn't do, then!"
Runkle found his man within five minutes, detached him from the other prisoners, and led him to the chart-room. Darrin tried his own German on the fellow, asking:
"Your craft had just arrived from the base port?"
The man stared, then slowly nodded.
"How many mines did you have on board when you left the base port?"
"Thirty, I heard."
"You planted some on the way?"
"A few, so I heard."
"Most of the mines you were to deliver here tonight?"
"Yes."
"How many trips a week has your craft been making between here and the base port?"
"Usually about four."
"Did you always deliver, here, to the same mine-layer?"
"No; that was as it happened. Sometimes to one boat, sometimes to another."
"How many mines could your craft carry?"
"Thirty."
As this agreed with the information supplied by Ensign Andrews, Dave believed that the seaman was telling the truth.
"Did your craft always come to these same waters to deliver mines to mine-layers?"
"Always, since I have been aboard, to some one of the shoals in this stretch of them," replied the sailor.
"Do you know how many mine-layers wait over here on the English side to have mines delivered to them?"
"No, but they are not so many."
"A few, supplied four times a week, can plant a lot of mines," quizzed Darrin.
"Oh, yes."
"And the craft you were aboard was one of the smaller ones that brought cargoes of mines. Your people have some that carry much larger numbers of mines?"
"Yes, and the larger boats that bring mines over to the real mine-layers travel faster under water than our boat did."
"So that these larger boats can make at least five round trips a week?" Dave asked.
"Oh, yes."
"You have not told me the name of your base port," Darrin went on.
"And I don't intend to," retorted the seaman."You are asking me too many questions. I should not have said as much as I did, and I shall not answer any more questions."
"You do not need to," Dave assured him. "I already know the answers to a lot of questions that I might have asked you. But you look like a reasonable fellow, and also like a fellow fond of some of the good things of life. Had I found you more ready to talk I might have arranged for you to have a pleasanter time in the English prison than your mates will have."
"A pleasanter time until the hangman called for us?" demanded the German, a cunning look coming into his eyes.
"The hangman?" Darrin repeated.
"Oh, yes! I know! We all know. The English hang the crews of German submarines. Our officers have told us all about it. You are wrong, too, to hang us, for it is the knowledge that the English will hang us that makes us fight more desperately when we are attacked."
"But the English will not hang you. You and your mates will be treated as prisoners of war," Darrin assured him. "You will be well fed. You will have some amusements. When spring comes you will have gardens to work in and the flowers or vegetables that you raise will belong to you. It is a stupid lie to tell you that the English hang you all. You will soon be on shore, and in anEnglish prison camp, and then you will know that you have been lied to. You will enjoy finding yourself on shore, for you were not often allowed to go ashore when you got back from these trips to take on your next mine cargo at—"
It was a simple trap, but as Darrin paused, the seaman replied:
"No, we were not often allowed ashore in ——," naming the port.
The port that the seaman mentioned was the one Darrin had been trying to get him to name. The German had unwittingly allowed himself to name the base port from which the mines were shipped. As soon as the German realized his blunder he used some bad language.
"That is all," said Dave Darrin. "You may go back to your mates, and by daylight you will know that an English military prison is not at all a bad place."
"Yousee," Dave nodded to his brother officers, "the theory we had worked out about the method of supplying mines to the submarine layers was the right one. I think that we shall be able to show some results to the admiral."
Dan was then instructed to remain to keep watch over the shoals, while the "Grigsby" soon afterwards started for port, escorting the two prizes.
Before daylight the captured under-sea boats were duly turned over to the British authorities. Darrin then sought the admiral, and, despite the lateness of the hour, he was soon admitted.
"What do you need for your enterprise?" inquired the admiral after listening attentively to the plan Dave had unfolded to him.
"Nothing but a dirigible, commanded by the right man," Dave explained.
"That ought not to be difficult," declared the British officer. "You shall have what you want. Now, suppose we go over the chart, to make sure that I understand just what you propose to do."
On the map Darrin traced the course that he felt sure the German underseas craft pursued when bringing cargoes of mines to the other submarines that were laying mines in British waters.
"That would be the natural course for such craft to take," agreed Admiral Wheatleigh. "I trust that you are right in your surmises. If you are, we should have some excellent results within the next few days."
"I shall know, sir, within forty-eight hours, and I think it likely that the enemy will also hear something about it within the next few days. At least, sir, the German admiralty should be able to guess."
Dave took his leave, hastening back to the "Grigsby," which, an hour later, weighed anchor and stood out to sea. By that time Dave was sound asleep, for he had been through a great deal and was sorely in need of rest before he reached the scene of his intended activities.
Some hours later he was called, and was soon on the bridge.
"You are at the point at which you wished to be called," said Fernald when Dave reached the bridge.
"And you will do well to seek your own rest now, Mr. Fernald," Darrin answered. "You can be called, if needed."
Half an hour later Darrin made out, in the skyastern, a tiny speck that rapidly came closer, and proved to be the dirigible sent at his request.
As the dirigible came nearer signals were rapidly exchanged. The course for the aircraft was made plain. As for the "Grigsby," her speed was slowed down to mere headway and she loafed over the waters.
Two hours passed during which the "blimp" aloft sailed rapidly to and fro in the sky, zig-zagging over the course in a way that covered several square miles in an hour.
"She's found something, sir!" cried Ensign Andrews.
"She has sighted a craft, bound over the course we had suspected," said Darrin, as signals broke out rapidly from the car under the big gas bag. "We'll let the submarine get by us before we start in chase."
Another half hour passed, for, though the dirigible moved swiftly, the underseas craft she was watching was moving only at submerged speed.
Then the chase led on past the "Grigsby." Purposely Darrin allowed it to go by him by about a mile ere he joined in the pursuit. Starting at half speed ahead he soon changed it to full speed.
And now the dirigible had slowed down, until she was travelling, as her signals stated, at just the speed of the submerged craft directly under her.
"We'll go in by the stern and try to make a quick job of it," Darrin proposed, as he gave Andrews final instructions, and turned to see that the signalman with his flag stood well aft on the superstructure.
As the destroyer raced in almost under the dirigible Darrin raised his right hand. The signalman with the flag did the same.
Just as the "Grigsby's" bridge passed in under the tail of the aircraft Dave Darrin read the signal for which he had waited. The airmen were telling him that the bridge of his craft was almost over the bow of the hidden enemy beneath.
Down came Dave's raised hand. Seeing it fall, the signalman let his flag drop.
In that same instant the depth bomb was released for its course over the "Grigsby's" stern.
Almost in the same second there sounded a terrific if muffled report under the surface. The water rose in three distinct columns, lifting the stern of the "Grigsby" and almost burying her bow under.
It was as though a great geyser and an earthquake had met. Columns like waterspouts hurled themselves across and over the reeling destroyer. Even when the "Grigsby's" nose came out and up once more the destroyer rocked in the near tidal wave that the swift series of explosions had produced.
"Pardon me, sir," begged Ensign Andrews, when he had regained control of himself. "I feel constrained to remark, sir, that you appear to know how to get all the thrills out of life."
"We must have landed right over a mine cargo once more," Dave answered smiling. "There were several explosions, but they came nearly together. One of these days we'll start something like that that will send us up half a mile into the air. But it's great sport, Andrews, especially when you pause to think what it all means."
"Great sport for us, but too sudden for the Huns," rejoined the watch officer. "They cannot have had the satisfaction, even, of realizing that anything had hit them."
Satisfied that there would be no more underseas explosions, Darrin gave the order to come about.
That the underseas craft had been struck was indicated clearly enough by the patches of oil on the water. The force of the explosion told the Yankee tars that the craft must have been blown into bits.
"Best thing I ever saw done!" signalled the British officer in command of the "blimp."
"Find us another, and we'll try to show you something just as good," Darrin caused to be signalled back.
Fernald, who had been called, having reported, was sent with the chief engineer to make a hullinspection below decks. Though some of the hull plates had been dented inward enough to attract attention, no leak could be found. The "Grigsby" was as seaworthy as ever, though after that rocking shock this seemed a marvel.
Off in the distance the "blimp" soon became a mere speck to the watchful eyes of those on the destroyer.
Dave directed that the aircraft be followed at cruising speed so long as she remained in sight. When the dirigible was at last lost to view the destroyer lay to, her lookouts using their glasses.
"Think the aircraft is coming back, sir," reported a lookout from the military mast.
From where he stood on the bridge Darrin could make out nothing for several minutes, though in the interval the lookout aloft reported that he could make out the "blimp" with surety, and that she appeared to be flying a signal, though he could not see what it was.
Then from the bridge the "blimp" became visible. A little later, too, the flag signal could be seen and read.
"Following another submarine," was what the signal said.
Going to starboard of the course Darrin advanced at ordinary speed to meet the "blimp," which, as in the former case, was flying just barely astern of the hidden monster, so that the forwardBritish airman lookout could discern the shape of the craft that was being pursued.
Dave waited until the dirigible had passed. He then gave the order, "Full speed ahead," and came about behind the "blimp."
Leaping forward the "Grigsby" gave chase, the "blimp" at the same time moving up directly over the intended prey.
At the drop of the flag above, Darrin let go his right hand, the signalman transmitted the order, and the bomb rolled overboard.
As Dave's hand fell the watch officer advanced the lever of the engine-room telegraph. An extra jump was put into the speed.
Again a column of water rose astern, but this time there was only the normal explosion of the depth bomb.
"Good hit," said the dirigible, by radio, and the message was called up to the bridge. "Saw her stagger. She's done for."
The "blimp" veered off once more, going back over her late course. As the "Grigsby" went about Darrin made out the tell-tale spread of oil on the waves.
"This is the real form of hunting," he exclaimed.
"Too bad, sir, that none of us thought of it before," remarked Ensign Andrews.
"We had to wait and learn," Dave explained. "That's the way that all progress in this war hasbeen registered. We are fighting an ingenious enemy. Destroying the submarine mine-carriers, as we are doing today, won't end the planting of German mines. As soon as the enemy finds out how we are checkmating him he'll invent another scheme, which we'll have to discover before we can beat it."
Half an hour later the British aircraft located a third submarine.
"A big one, too," she signalled. "Following the same course."
"Mr. 'Blimp' might try a bomb himself," suggested Ensign Andrews. "I believe he carries a few."
"Not as powerful ones as we carry," Darrin answered. "Besides, he has to be at a greater altitude, when hunting submarines, than it's handy to drop a bomb from. There is too much margin of chance that the enemy craft will graze by when the bomb is dropped from the air. In our case, if we drop when directly over the Hun, there can hardly be a miss, and it's the dirigible's business to tell us when we are directly over the enemy."
In the meantime, on board the destroyer, all was made ready, and Dave followed the same tactics as before. This time, too, there was a normal explosion, though a solid hit was made and the submarine destroyed. Apart from the "blimp's" report there could be no doubt as to thedestruction. The spread of oil on the surface of the sea told the story.
"If you and we hurry, we may bag another before dark," Dave sent by wireless, as the aircraft started back again.
"We'll do our best, believe us!" came back the word.
In the late afternoon a slight haze came up, which gradually deepened.
Darrin followed for a few miles, keeping the "blimp" in sight. She was some six miles away when a radio message came from her in code in these words:
"Can you see steamship about four knots north-west of us?"
Dave challenged the lookout on the militarymast, but that seaman reported the weather a bit too thick to enable him to make out the steamship. Darrin accordingly wirelessed back this information.
"Looks like a tramp steamer," came the next message, "but she acted suspiciously when she sighted us. Her skipper appears perturbed, which he would hardly be if his business is honest. Weather is thickening so we may lose him in the haze. Better close in."
"Will do so," Dave replied.
Then followed explicit directions as to the course the destroyer must follow.
The next code message from the airship was:
"Skipper of steamship so bothered that he appears to be rigging anti-aircraft gun. Am about to signal him to stop for search."
Despite the haze over the sea the "blimp's" movements could still be made out from the deck of the destroyer. Mast lookouts and those on bridge and deck followed the "blimp's" movements with keen interest.
"He maneuvers as if he were closing in on the steamship," declared Ensign Andrews.
"If the steamer's skipper uses anti-aircraft guns the dirigible's commander will be justified in dropping bombs," Dave returned. "It's a stupid piece of business for any lightly armed steamer to attempt to resist a 'blimp.' But of course the steamer's skipper does not know that there is a warship so close."
"The rascal's firing on us," reported the "blimp."
"If you'll keep back we'll close in and talk to the stranger," Darrin suggested, by wireless.
"We're hit," almost instantly came the report from the airship.
"Badly?" Dave asked by radio.
"Investigating. Report soon."
"That ship must be up to something extremely desperate to dare to fire on a British 'blimp'!" exclaimed Dave Darrin. "But we're getting close, and soon ought to know what we have to tackle!"