"He's a wrong 'un, sir," exclaimed the Customs man. "You had better inform the police."

"Haven't time," exclaimed Hythe savagely, and without another word he ran towards the steps at the New Mole. When he arrived it was ten minutes past six, and no signs of Kenwyn and Gwennap were to be seen.

"That's done it!" e.j.a.c.u.l.a.t.ed the sub. "And Captain Restronguet said six o'clock sharp."

CHAPTER XVI.

OVER A VOLCANO.

If ever a man felt like kicking himself it was Arnold Hythe at that moment. He had missed his appointment; and in Captain Restronguet's eyes he would be regarded as a waster devoid of any sense of honour or grat.i.tude.

"Have you seen anything of two divers?" he asked, addressing the crowd that lingered about the landing; for, though the time fixed for his departure had been kept a secret, a curious throng had loitered there nearly all day.

"Yes," shouted a dozen voices in chorus, and amid a babel of vociferations the sub contrived to gain the information that they had appeared quite half an hour ago, had waited ten minutes and had disappeared.

"Are you quite sure they went before six?" asked Hythe.

"Perfectly sure, sir, it was exactly ten minutes to six when they went down," replied a sailor confidently.

Then the thought flashed across his mind, perhaps Captain Restronguet had purposely marooned him? An instant later he banished the suggestion, yet why should Kenwyn and Gwennap have returned before the appointed time?

Hythe resolved to wait and see if anything fresh transpired. The crowd increased, several naval officers and dockyard officials mingling in the throng. Presently the Admiral came down and asked if he should order anything to be done to attract the "Aphrodite's" attention.

"They may come back even yet, sir," replied the sub. "I'll wait a little longer."

"If you hear nothing by seven you may as well have dinner at Admiralty House, Mr. Hythe," observed the Admiral.

Just at that moment two men in uniform arrived carrying Hythe's trunk.

The thief had been caught and was under lock and key.

"That's something to be thankful for," soliloquized the sub. "To lose one's belongings and one's ship at one time is a bit too thick."

A sudden shout of exclamations from the crowd caused him to turn and look towards the slide of the Mole. Like a huge porpoise the twin conning-towers and flat deck of the "Aphrodite" appeared upon the surface, the water pouring in cascades from her smooth substance. As easily as a ship's pinnace she ran alongside the steps, her after-hatch was thrown open and Captain Restronguet appeared.

"Come on, Mr. Hythe!" he exclaimed.

The sub waited for no second bidding. With a bound he gained the Upper Platform, and turned and saluted the astonished Admiral. Having seen his belongings pa.s.sed on board he followed his host below.

Fifty seconds later the dense crowd of spectators were gazing dumfounded at the unbroken wavelets. For the first time had human eyes, other than those of her crew, seen the redoubtable "Aphrodite" at close quarters above the surface of her natural element.

"Yes, I was certainly surprised when Kenwyn returned with the news that you were not at the rendezvous, Mr. Hythe," said Captain Restronguet.

"Then the thought suddenly struck me."

"What thought, sir?"

"Might I ask what time you went by?"

"The local time; my watch had stopped. By Jove! I see what happened.

Gib. time is 21 minutes 28 seconds slower than Greenwich."

"Just so. I guessed the mistake arose that way; so, as a considerable amount of precious time would be wasted in sending Kenwyn and Gwennap ash.o.r.e again, I took the unusual course of bringing the 'Aphrodite'

right alongside the New Mole. It will give the Scorpions something to talk about."

"And the naval authorities as well, sir. The Admiral was there."

"Now we are off as hard as we can pelt for the Eastern Mediterranean. I mean to keep at good depth till clear of the patrols of the Straits. The 'Vorwartz' is reported in the Black Sea, so I suppose the Russians will get excited. Anyway, I hope to be able to arrive in the aegean Sea and intercept Herr Karl von Harburg as he returns through the Dardanelles."

Night had fallen ere the "Aphrodite" rounded Europa Point, and with the favouring east-going current was well beyond the cruising ground of the British submarines.

Two days later she was between Cape Bon on the Tunisian sh.o.r.e and the western extremity of Sicily. Captain Restronguet had, in view of recent developments, decided not to touch at Malta, but proceed as fast as he could to Grecian waters, where he hoped to be able to replenish his acc.u.mulators and be in a state of readiness for his hated rival.

Hythe had retired to his bunk. He had had a heavy day in the conning-tower, where, in reply to his host's invitation, he had stood a watch in order to acquaint himself with the delicate organization of electrical mechanism that controlled the submarine.

The "Aphrodite" had been running on the surface during the day, but to obviate the risk of being struck by pa.s.sing vessels she was submerged to nine fathoms at sunset.

Suddenly the sub found himself struggling on the steeply listing floor of his cabin. The place was in utter darkness. All around him were weird noises caused by various articles breaking adrift, mingled with the shouts of the alarmed crew, while from without came an awe-inspiring rumble.

Struggling to his feet the sub groped for the electric light switch.

The current was off. More and more became the list till his feet slipped from under him, and he fell into the angle formed by the floor and the fore and aft bulkhead of the cabin. Above the noise he could distinguish the captain's voice shouting for the emergency ballast tanks to be emptied.

"Good heavens! She's been struck. We're done for this time," exclaimed Hythe, with lively recollections of the ill-fated "La Flamme" fresh in his memory. He gained his feet and made for the door, but ere he could fling it open the "Aphrodite" spun round as if pivoted amidships. Full length went the sub once more, his hands grasping the k.n.o.b of the door, which had come off in the strain. The racket of the shifting gear was redoubled. Every moment Hythe expected the enormous pressure of water, since he was fully certain that the vessel was plunging downwards, would burst in the sides of the submarine.

Another nerve-racking twist and the "Aphrodite" began to dip her bows till this time the sub found his sliding movement checked by the fore and aft bulkhead. Then, with a rattle and clank of her complicated machinery, the propellers began to race, while the vessel danced about like a gigantic cork. Instead of plunging down the submarine had been raised to the surface, and was being tossed about on the crests of an angry sea.

After considerable trouble Hythe succeeded in opening the door. Outside in the alley-way all was in darkness. He groped his way towards the fore conning-tower, staggering against the metal wall with each abnormal heave of the vessel. Before he had traversed many feet he came into violent contact with a man whom he recognized by his voice as the chief officer.

"What's up, Devoran?" he asked.

"Heaven only knows, Mr. Hythe. Until we get the light switched on it will be difficult to find out. One thing, we are afloat, and riding easily."

"Much too easily for my liking," remarked Hythe, although he felt considerably rea.s.sured that the "Aphrodite" had risen.

"Where are you going?" asked Devoran.

"To the for'ard conning-tower."

"No use," replied the chief officer laconically. "All princ.i.p.al watertight doors are closed. Captain's for'ard. Best to go to the after conning-tower if you want to see anything. I left Kenwyn there."

The sub made for the steel ladder communicating with Kenwyn's post, and as he did so he heard Devoran raise the flap of the hatchway to the motor-room and ask Carclew what in the name of Pontius Pilate's grandmother was the matter with the light?

"Plug fused, sir. I am replacing it," shouted Carclew.