Shaunessey are prisoners on the submarine. Furthermore, a telegram from Dantzic announces that Captain Restronguet--confound that fellow!--has destroyed the armoured cruiser 'Breslau.'"

"When was that, sir?" asked Captain Tarf.a.g.

"The message from Dantzic is dated 8 a.m. this morning. Allowing for differences in Greenwich time----"

"Then, if the submarine we were after is under the command of Captain Restronguet, it is morally impossible for him to be in the Baltic at precisely the same hour----"

"Unless there are two of these blessed submarines."

"Or two captains of the name of Restronguet," added Captain Tarf.a.g.

"I suppose this fellow means to hold Mr. Hythe to ransom, sir?" asked Mr. Egmont.

"There is no mention of that," replied the Admiral. "But, of course, that may be his intention. I wonder where the mysterious submarine will turn up next?"

"The Superintendent of Police, sir," announced the head-messenger.

"Ah, Richardson, what's the trouble now?" asked the Commander-in-Chief, as a tall, alert-looking man stepped briskly into the room.

"More evidence of Captain Restronguet, sir," replied the Superintendent of Police. "The rascal's actually in the Hamoaze. Our duty boat, whilst returning from Bull Point, picked up a green and white buoy, just abreast of Wilcove. Attached to the buoy, and protected by a water-proof covering, was this doc.u.ment."

The admiral took the paper--a foolscap sheet, with a crest and the words "Submarine 'Aphrodite'" embossed upon it. In silence he read it to the end, then--

"Well, of all the most confounded cheek!" he e.j.a.c.u.l.a.t.ed. "Read that, Tarf.a.g, and tell me what you think of it."

"I have the honour to acknowledge the receipt of the Admiralty's message of even date. In order to prove conclusively that this reply is authentic, I have taken steps to see that this doc.u.ment is placed in the hands of the Commander-in-Chief of the Devonport Command. Mr. Arnold Hythe and A.B. O'Shaunessey, official number K14,027, are on board my vessel 'Aphrodite.' In the interests of the Service, and also in my own, it is desirable that Mr. Hythe remain on board for a period not exceeding six months. Any information the officer in question may gain is entirely at the disposal of the British Admiralty, and since the possibilities of so doing are great, I would suggest that covering permission be given for Mr. Hythe's absence from his official duties.

Incidentally I may mention that this suggested permission is merely formal, for in any case my guests will not be put ash.o.r.e until I think fit.

"I am at present giving a series of demonstrations in British waters, but not with any aggressive intent. It is hopeless to attempt the capture of my submarine, and no useful purpose will be thereby served.

"I take this opportunity of explaining the cause of the hostile acts committed against an outwardly friendly State, in the hope that the calamity of a great war may be averted.

"The submarine in Baltic waters is the property of Karl von Harburg, a German renegade, who has certain motives in committing these excesses, which can neither be justifiable nor excusable. His submarine, itself a craft of great abilities, is but a feeble imitation of my 'Aphrodite.'

It will not help matters to any great extent by explaining my reasons, but I can a.s.sure you that at the first available opportunity I mean to destroy the submarine owned and commanded by Karl von Harburg, as I regard the man as an unprincipled international scoundrel and a scourge to humanity.

"Will you kindly forward this doc.u.ment to the Secretary of the Admiralty, and inform him that my agent will receive his reply per telephone, at the hour of 10 a.m. to-morrow.

"I have the honour to be, Sir, "Yours, etc., "JOHN RESTRONGUET."

CHAPTER IX.

THE FIRST DAY IN THE "APHRODITE."

A bell rang out sharply in the captain's cabin of the "Aphrodite," and one of the electric indicators oscillated rapidly.

"Acc.u.mulators charged," announced Captain Restronguet laconically.

"It is a revelation to me," said Hythe. "And when one comes to consider that at every hour of the day hundreds, nay thousands, of ships are straining idly at their moorings, it is certainly remarkable that no satisfactory attempt has. .h.i.therto been made to harness the tides."

"That's only one of the many lessons you will learn," remarked the Captain. "But we are getting under way once more. Perhaps you would like to see the mechanism on Number Three Platform?"

"Most certainly I should," replied the sub.

In the alley-way they encountered a short, broad-shouldered man who had to set his back against the metal wall in order to allow his captain to pa.s.s.

"All correct, sir," he said saluting.

"Right, Mr. Devoran. Who's in the conning-tower?"

"Mylor, sir."

"Good. I will take the 'Aphrodite' up the river. You need not turn out till midnight. I shall want you then."

"That is my chief mate, Mr. Devoran," remarked Captain Restronguet, after the man had gone to his cabin. "A truer-hearted comrade one could not possibly desire. He is the only man on board beside myself who thoroughly understands the whole of the complicated mechanism of my masterpiece. There are others who are capable of manoeuvring the 'Aphrodite,' but they do not understand how to handle her for offensive purposes."

Throwing back a watertight sliding-door in the port fore and aft bulkhead Captain Restronguet signed to the sub to enter. Hythe found himself in a small compartment on the walls of which were several articles and gear. No s.p.a.ce was wasted on board the "Aphrodite."

In the centre of the floor was an oval-shaped aperture, sealed with a rubber-lined lid, that by means of double levers could be opened from either above or below. As the hatch opened Hythe saw a portion of the well-lighted interior of the lower deck, access to which being gained by means of a vertical steel ladder.

The for'ard compartment, extending the whole length and breadth of the foremost section of the submarine, with the exception of the s.p.a.ce taken up by the diving-exit, was as far unlike the forehold of a ship as the sub could possibly imagine. The cement-cased walls were distempered a pale green; thick corticene--a kind of linoleum used in the Navy--covered the floors; alongside the after bulkhead were two arms-racks filled with automatic rifles and pistols, and other modern small-arms. Secured to the deck was an automatic one-pounder field-gun.

Towards the bows were two long narrow tubes, the external diameter by less than seven inches, while a seemingly complicated arrangement of double-locking doors, electric wires, trippers and gauges suggested to the sub that these instruments were torpedo tubes.

"Quite right," said Captain Restronguet in reply to Hythe's question.

"A pair of six-inch tubes firing electrically directed torpedoes. They will never miss their target, I can a.s.sure you, even at five miles range, if controlled from a lofty station. Here we are limited, but so long as we can see our target by means of our flexibly attached periscope, there is a million chances to one on the weapon striking the mark. But listen!"

The hiss of a powerful water jet was just audible through the double plating of the submarine's hull.

"Merely a precautionary measure to clear the holding plates of mud and seaweed," explained Captain Restronguet. "If the spades, as I might term them, do not fold absolutely flush with the vessel's bottom, there's bound to be a tremendous resistance to the water and consequently a serious loss of speed. Now the jet is turned off.

Listen again and you will hear the anchor plates come home."

"That they are!" exclaimed the sub, as a distinct thud shook the plates under his feet. "I suppose they are lifted by metal rods working in water-tight glands?"

"Oh, no; merely by the attraction of electromagnets. Every valve and door in this vessel is electrically controlled, although in some cases, such for instance the hatch by which we gained this compartment, manual power can be used. When next an opportunity serves I will show you the engine-room, but we are about to rise now. I must go to the for'ard conning-tower. You may come, too, if you feel inclined, or if you prefer there is a private cabin at your disposal."

"How does the submarine rise, might I ask? By means of horizontal rudders?"

"Yes and no," replied Captain Restronguet. "But before I explain perhaps this might interest you."

Stepping over to where three levers stood in the centre of the compartment the captain thrust one hard down. Instantly a portion of the floor opened. Another lever caused a corresponding part of the outer plating to slide back, revealing an observation plate of about three feet by two through the double skins of the starboard bilge-plates.

"I can see nothing," said Hythe, as he strove to peer through the gla.s.s.

"It is perfectly dark."

"There ought to be sufficient light at this depth to see fairly well, but since the 'Aphrodite' is still on or nearly on the bottom of The Narrows, the hull intercepts what little light there is to penetrate the water. Now look!"