A better place to effect the capture of the submarine could hardly be found, for the depth shelved gradually from twenty feet close insh.o.r.e to forty along a line joining the extremities of Penlee and Picklecombe Points.

The after-decks of the two surveying vessels were buried beneath piles of nets composed of three-inch tarred rope intermeshed with flexible steel wire. These could be "paid-out" with considerable rapidity, and being buoyed and weighted would sink automatically till their upper edge was ten feet below the surface and their lower edge the same distance from the bottom. Both vessels were to start simultaneously from the western extremity of the Breakwater and head for Penlee and Picklecombe Points respectively, where strong parties of seamen were ready to haul the ends of the nets ash.o.r.e.

At half-past five Captain Tarf.a.g gave the order to commence paying out the obstructions, and at a steady six knots the "Investigator" steamed ahead, her consort, being a slower vessel, having to take the shorter distance--that between the Breakwater and Picklecombe. Precisely at five minutes to six the sh.o.r.eward ends of the nets were secured.

"If Captain Restronguet keeps his promise he is already safe in the net!" exclaimed Lieutenant Egmont. "You see, there is nothing to prevent him from giving his signal at the appointed time. There are no vessels in the bay, and no aircraft overhead."

"It will be a nasty shock to those craft if he fires a rocket over their heads," remarked Arnold Hythe, indicating the crowd of small vessels that, in spite of the picquet-boats, were continually edging nearer and nearer in the desire of their occupants to see more of the promised "fun." "But what is going to happen when we trap the submarine?"

"Oh, Captain Tarf.a.g and I have already settled about that," replied the navigating lieutenant confidentially. "As soon as we are certain that the submarine is in the bay parties of men ash.o.r.e will drag in the nets, till the craft is either stranded or her propellers are hopelessly entangled in the rope and wire strands. But stand by! It's close on six."

A hush fell on the a.s.sembled mult.i.tudes. Every face was turned in the direction of the tranquil bay, where, save for a slight ground-swell, the water was unruffled.

The crowds were not kept waiting. Punctually to the minute, at less than four hundred yards from sh.o.r.e and almost abreast of the little village that gives the bay its name, a green and white flag, hanging limply from a staff by reason of the saturated state of the bunting, rose above the surface. Then urged by some unseen power the flag-staff ripped its way through the water, throwing the spray in silvery cascades. Then it described a circle of less than a hundred yards in diameter, then as abruptly as it appeared the emblem of the mysterious Captain Restronguet vanished beneath the surface.

"We've got him, by Jove!" shouted Captain Tarf.a.g.

Four blasts in rapid succession from the "Investigator's" syren was the signal for the men ash.o.r.e to haul away.

Slowly the ponderous line of netting was dragged through the water.

Fortunately there was little or no tide and hardly any floating weed to render the task more difficult than it might otherwise have been; nevertheless it required an hour's hard work ere the enclosed s.p.a.ce marked by the line of buoys appreciably diminished.

All the while signals from the "Investigator" were being exchanged with the look-out tower on Penlee Point. Again and again came the disquieting news "No sign of submarine."

"Surely in fifty feet, with a clear sandy bottom, those fellows up there ought to detect the craft!" exclaimed Lieutenant Egmont impatiently.

"I failed to see it at ten yards, although I admit the water was awfully muddy," said the sub.

"But what if she's given us the slip?" continued the navigating lieutenant. "Look, man; in another half an hour the bight of the net will come ash.o.r.e."

"A lot may happen in half an hour," replied Hythe. "Unless she uses an explosive to clear a pa.s.sage we have her safe enough, and I do not think that Captain Restronguet will resort to extreme measures, judging how he has already behaved in British waters."

"What I want to know is how Captain Tarf.a.g proposes to take possession of her, when she is held up in the nets. He told me he had a plan, which we are now carrying out, but not a word more on the subject would he say, so, of course, I couldn't offer any suggestions."

"It is nearly high-water springs," observed the sub. "That means that we could get her sufficiently high for the falling tide to leave her stranded. Hulloa! What's that?"

A sudden commotion at less than a cable's length on the "Investigator's"

starboard bow showed that some large moving object had been held up in the stout meshes of the net. Myriads of air-bubbles rose to the surface, causing a considerable patch of broken water on the otherwise smooth sea. A light-draught picquet boat, with two heavy grapnels made ready to lower, dashed over the submerged net. The iron hooks fell with a dull splash.

"Holding, sir!" shouted the midshipman in charge of the picquet-boat.

"Good! Belay there!" replied Captain Tarf.a.g. "Drop the second grapnel, and I will send a boat to bring the rope aboard."

The working parties ash.o.r.e desisted in their efforts. All the power at their command could not bring the nets home another fathom. Held by the submarine, that in turn was tenaciously anch.o.r.ed to the bottom of the bay, they absolutely refused to be hauled in. A sounding gave a depth of seven and a half fathoms.

"Mr. Hythe," shouted the captain.

The sub took the bridge-ladder at top speed, and saluting, awaited his chief's orders.

"Oh, Mr. Hythe," continued the latter. "I want to send a couple of men down to report on the position of the submarine. If she's anch.o.r.ed, get them to find out in which direction her cable leads and we can then creep for it. Also I want to ascertain whether it be possible to lower the bight of a chain under her bow and stern. If that can be done I'll signal to the Dockyard for a couple of lighters, and we'll lift the craft with the rising tide and take her straight into the Hamoaze. But mind, Mr. Hythe, I wish it to be distinctly understood that volunteers only are required for this service."

"I should like to descend, sir."

"You! Why I thought, by Jove, you had enough of it on the last occasion you encountered the submarine, judging by all accounts. But of course, I should be glad to accept your offer. Take two men with you."

The sub again saluted, and on gaining the quarter deck ordered the bo's'un's mate to pipe away the diving-party.

Of the qualified divers every man-jack expressed his desire, as vehemently as the presence of the officers permitted, to go down. Hythe would have much preferred to have taken Moy and Banks, who at his request had been transferred from the "flagship, but favouritism he strongly set his face against.

"Numbers one and two front rank men, fall out."

Number one was a tall, broad-shouldered Irishman named O'Shaunessey, a man who still retained the Wexford brogue. Number two was a dapper little c.o.c.kney, Price by name, who had the distinction of holding the Navy record for deep-sea diving.

"Look here, Price," said the sub, "I'm going down too; but I want you to clearly understand what to do. I will try to locate the Submarine, and see if there is any possibility of raising it by means of a grapnel.

You I want to get as close to the bows as you can without much chance of being seen and report by telephone what forefoot she has, if any, and if there's any chance of slinging her at that end. O'Shaunessey, I want you to examine the after-end, and find out what overhang she has; also whether her propellers are foul of anything."

"Hurry up, there!" ordered Captain Tarf.a.g. He was naturally anxious that his prey should not escape him, for, although the strain on the picquet boat's grapnel-line was maintained, the bubbles no longer rose from the enmeshed submarine.

Hythe was the first to descend, from a boat lowered from the "Investigator." The conditions beneath the surface were far more favourable than on the occasion of his descent at Spithead, for the bottom was of firm white sand, and the tidal current was barely a quarter of a knot.

Ere he had traversed fifty yards an ill-defined ma.s.s loomed up ahead of him. It was the submarine, exaggerated out of all proportion by the refractive properties of the water.

With rapidly beating heart the sub continued to advance. Suddenly he saw a figure in diver's dress approaching. He stopped. The stranger stopped too.

"I'll wait for Price and O'Shaunessey," thought Hythe, and still keeping his face towards the unknown diver he laboriously retraced his steps. As he did so the stranger did likewise.

"I wonder----" thought the sub, and raising his right arm he saw the unknown diver simultaneously raise his left. Hythe was confronted by a magnified reflection of himself. The sides of the submarine were made of a mirror-like substance.

Keeping a respectful distance from the submerged craft Hythe walked towards, but parallel to, the bows. Presently he became aware that he was pa.s.sing under the lowermost edge of the net, that, with elongated meshes, was stretched tightly across the upper portion of the stem of the submarine.

Since nothing had attempted to molest him, Hythe's sense of confidence rose.

"No, they wouldn't dare play the fool now," he reasoned. "There's no escape for them, and they will make the best of a bad job by surrendering at discretion as soon as the lighters sling her clear of the bottom. I wonder where her cable is?"

No signs of the submarine's anchor and chain were visible. There were hawse-pipes--two on the starboard bow and one on the port bow, but in none of them was a stockless anchor, or indeed one of any description.

The hawsepipes were partly concealed by the nets, but the meshes were sufficiently distended to make the sub certain on that point.

Keeping his eyes fixed upon the ground Hythe walked on, thinking that, from the position of the vessel, he would eventually stumble over an anchor and chain lying half-buried in the sand. At length he came to the limit of his life-line, his search unrewarded.

"That's completely stumped me--middle wicket, by Jove!" he muttered. "A looking-gla.s.s submarine fixed as tight as a limpet to the sand, and not an anchor to be seen! All in good time, I suppose. When we get her into Plymouth we'll find out all we want to learn soon enough."

With that he turned and began to make his way round the submarine once more.

"Oh, there's O'Shaunessey!" he said to himself, as a huge helmeted figure came shambling along through the semi-transparent water. "I wonder what---- Great Scott!"

Arnold Hythe came to an abrupt stop. The diver approaching him was not O'Shaunessey. The Irishman's helmet was provided with an air-tube, and a life-line encircled his chest; this fellow had neither. He was one of the crew of Captain Restronguet's submarine.

The sub was not devoid of personal courage. The sight of the strange diver advancing in his direction aroused all the bull-dog fighting instinct in him.