class="pnext">Up from below tumbled the diving-party. Air-pipes, life-lines, pumps, dresses, and helmets were produced from some remote yet properly apportioned part of the ship and were thrown down in a seemingly chaotic manner upon the steel deck. Actuated by electric power several sections of the armoured shields between the upper deck and the eaves of the V-shaped shell-proof roof were lowered till they lay flat upon the deck, and steel ladders for the divers' use were rapidly placed in position.

"Do you wish me to go down, sir?" asked a sub-lieutenant of the Number One.

"Certainly, Mr. Hythe," replied the first lieutenant. "Make a careful examination for a radius of say fifty yards from the shot-rope. You will doubtless be able to see the place where the flukes of our anchor held before. Ascertain if there are any traces of independent work; such as footprints in the ooze, tracks of the underbody of a submarine settling on the bottom, for example."

"Very good, sir," replied the sub, who, saluting, went off to be assisted into his diving-dress.

Sub-lieutenant Arnold Hythe was generally regarded as a smart and promising young officer. These golden opinions were gained not by self-advertisement, for the sub was unusually reticent concerning his profession, but by sheer hard work and a consistent application to that great deity that should always be before the eyes of all true subjects of the King--Duty.

He held a First-class certificate in Seamanship, Gunnery, and Engineering; a Second in Torpedo, and also in what the Navy List terms "Voluntary Subjects"; he was a qualified interpreter in French and German, and had more than a smattering of Spanish and Italian. In addition to these intellectual qualifications he possessed a powerful physique, and had a sound reputation as an all-round athlete whilst at Dartmouth.

The latter portion of his time as midshipman and the first few months after his promotion to sub-lieutenant were spent in duty with the Fifth Submarine Flotilla, whose base was at Fort Blockhouse at the entrance of Portsmouth Harbour. But through some cause, to him quite inexplicable, he had been appointed to the "Ramillies." This was somewhat to the sub's disgust, but realizing that it was of no use repining over such matters, Arnold Hythe accepted the change with cheerful alacrity.

Banks and Moy, the two seamen divers who were also to descend, were already dressed. All that remained was for their copper helmets to be donned, the telephones and air-tubes adjusted, and the glass fronts screwed on.

"I don't expect you will find any actual evidence, and it will be lucky if you come across any circumstantial evidence," remarked Mr. Watterley, the first lieutenant. "But in any case, should you see anything of a suspicious nature, inform us before proceeding to investigate. I need not remind you that the east-going tide is making, and that the current will be running fairly strong in a few minutes."

"Very good, sir."

Sub-lieutenant Hythe was a diver of considerable experience. Ever since his first descent in the training tank at Whale Island he took naturally to the hazardous duty. Going under the sea had a peculiar fascination for him, whether it was in the hull of a submarine or encased in the cumbersome india-rubber suit and ponderous helmet of the diver.

The men at the air-pumps began slowly to turn the handles. The glass front plates of the sub's helmet were secured, and assisted by a seaman Hythe staggered awkwardly towards the head of the iron ladder.

Rung by rung he descended till the water rose to his shoulders.

"By Jove, the tide does run," he muttered. "If it's like this now, what will it be in another ten minutes?"

Raising one arm he waved to those on deck, then releasing his hold he allowed himself to drop into the deep. The "Ramillies" was anchored in nine fathoms, but ere the sub reached bottom nearly a hundred and twenty feet of life-line and air-tube were paid out. With an effort he gained his footing and commenced to walk in the direction of the ship's anchor, battling against the two-knot current that swirled past him.

Although the sun was shining brightly and the light at that depth ought to be fairly strong, the sand and mud churned up by the tidal current made it impossible to see beyond a few yards. With nothing to guide him, for the life-line was quivering in the swirling water, Hythe struggled stolidly in the supposed direction. He realized that he was practically on a fool's errand. The mysterious person or agency who had been responsible for attaching the message to the anchors of the squadron was not likely to remain upon the scene of his exploit, while already all the sought-for traces must have been obliterated by the tide.

Presently two eerie-looking shapes ambled towards him. They were his companions, Banks and Moy.

"Well, if I am going in the wrong direction, those fellows are making the same mistake," thought the sub. "So here goes."

Another thirty yards were laboriously covered. Here and there the divers had to make a detour to avoid the wavy trailing masses of seaweed, that, if not actually dangerous, would seriously impede their progress, while at every few steps numbers of flatfish, barely discernible from the sand and mud in which they were partially buried, would dart off with the utmost rapidity.

"Thank goodness, here's the shot-line," exclaimed the sub, as a thin rope, magnified under water to the size of a man's wrist, became visible in the semi-gloom. The shot-line, terminating in a heavy piece of lead, had previously been lowered to serve as a guide for the divers to work from.

Pointing in two opposite directions Hythe signed to the two men to begin their investigations, while he, taking a route that lay at right angles to the others' course, began once more to struggle against the current. Ere he had traversed another ten yards his feet slipped into a slight depression. It was the hole scooped out by the flukes of the "Ramillies'" stockless anchor.

"Could do with a lamp," he remarked to himself, then stooping he began to examine the bed of mud and sand in which he stood. Beyond the almost filled-in cavity and the faint traces of the sweep of the battleship's anchor-chain there was nothing to attract his attention. He turned to look at his own footprints. They were already practically obliterated, so it was hopeless to expect to find the footprints of the mysterious diver or divers who had contrived to visit each of the anchors of the battleships in turn.

"Anything to report?" asked a voice through the telephone.

"No, sir," replied the sub.

"Thought as much," said Watterley. "Merely a matter of form. You may as well come up. I'll recall the two men."

Sub-Lieutenant Hythe was not sorry to hear the order to return. Had there been any possibility of success he would have prosecuted his investigations with alacrity, but Spithead with an east-going spring tide running is no place to indulge in submarine excursions. The danger of getting life-line and air-tube foul of some unseen obstruction was no slight one.