do."

"I think so, sir," said the Lieutenant, saluting.

The Lieutenant-Commander walked from port to starboard and starboard to port thinking pretty hard until the navigating lieutenant came to take charge of the bridge. Of submarines he knew a good deal. He knew that the British navy possessed the very best type of this craft which navigated the under-waters. He had also, of course, read the aërial experiments which had been made by inventors of what the newspapers called airships, and which he, with his hard naval common-sense, called gas-bags with motor engines slung under them. He knew the deadly possibilities of the submarine; the flying gas-bag he looked upon as gas and not much more. The real flying machine he had considered up till a few moments ago as a dream of the future; but a combination of submarine and flying ship such as he and Castellan, if they had not both been drunk or dreaming, had seen a few moments ago, was quite another matter. The possibilities of a thing like that were absolutely limitless, limitless for good or evil, and if it did belong to a possible enemy of Britain, there was only one conclusion to be arrived at—The Isle Inviolate would be inviolate no more.

Lieutenant Franklin came on to the bridge and saluted; he returned the salute, gave the orders for changing the course, and went down to his cabin, muttering:

"Good Lord, if that's only so. Why, half a dozen things like that could fight a fleet, then go on gaily to tackle the forts. I wonder whether my Lords of the Naval Council will see me to-morrow, and believe me if they do see me."

By great good luck it happened that the Commander of the North-eastern District had come up from Hull to Scarborough for a few days' holiday. When he saw the Cormorant steam into the bay, he very naturally wanted to know what was the matter, and so he went down to the pier-head, and met the Cormorant's cutter. As Erskine came up the steps he recognised him and saluted.

"Good-morning, sir."

"Good-morning, Erskine. What's the matter? You're a little off your ground, aren't you? Of course, there must be a reason for it. Anything serious?" replied the District Commander, as he held out his hand. "Ah, good morning, Castellan. So you've both come ashore. Well, now, what is it?"

Erskine took a rapid glance round at the promenaders who were coming down to have a look at the cruiser, and said in a low tone:

"Yes, sir. I am afraid it is rather serious; but it is hardly the sort of thing one could discuss here. In fact, I was taking the responsibility of going straight to London with Castellan, to present a report which we have drawn up to the Board of Admiralty."

The District Commander's iron-grey eyebrows lifted for the fraction of a minute, and he said:

"H'm. Well, Erskine, I know you're not the sort of man to do that sort of thing without pretty good reason. Come up to the hotel, both of you, and let us go into it."

"Thank you, sir," replied Erskine. "It is really quite fortunate that we met you here, because I think when you've seen the report you will feel justified in giving us formal leave instead of French leave."

"I hope so," he replied, somewhat grimly, for a rule of the Service had been broken all to pieces, and his own sense of discipline was sorely outraged by the knowledge that two responsible officers had left their ship with the intention of going to London without leave.

But when he had locked the door of his sitting-room at the hotel, and heard the amazing story which Erskine and Castellan had to tell, and had read their report, and the evidence of the men who had also seen the strange apparition which had leapt from the sea into the air, and then returned to the waters, he put in a few moments of silent thinking, and then he looked up, and said gravely:

"Well, gentlemen, I know that British naval officers and British seamen don't see things that are not there, as the Russians did a few years ago on the Dogger Bank. I am of course bound to believe you, and I think they will do the same in London. You have taken a very irregular course; but a man who is not prepared to do that at a pinch seldom does anything else. I have seen and heard enough to convince me for the present; and so I shall have great pleasure, in fact I shall only be doing my duty, in giving you both leave for a week.

"I will order the Seagull up from Hull, she's about ready, and I think I can put an Acting-Commander on board the Cormorant for the present. Now, you will just have time for an early lunch with me, and catch the 1.17, which will get you to town at 5.15, and you will probably find somebody at the Admiralty then, because I know they're working overtime. Anyhow, if you don't find Sir John Fisher there, I should go straight to his house, if I were you; and even if you don't see him, you'll be able to get an early appointment for to-morrow."

"That was a pretty good slice of luck meeting the noble Crocker, wasn't it?" said Castellan, as the train began to move out of the station, about three hours later. They had reserved a compartment in the corridor express, and were able to talk State secrets at their ease.

"We're inside the law now, at any rate."

"Law or no law, it was good enough to risk a court-martial for," said Erskine, biting off the end of a cigar. "There's no doubt about the existence of the thing, and if it doesn't belong to us, which is a fact that only my Lords of the Naval Council can know, it simply means, as you must see for yourself, that the invasion of England, which has been a naval and military impossibility for the last seven hundred years or so, will not only become possible but comparatively easy. There's nothing upon the waters or under them that could stand against a thing like that."

"Oh, you're right enough there," said Castellan, speaking with his soft West of Ireland brogue. "There's no doubt of that, and it's the very devil. A dozen of those things would play havoc with a whole fleet, and when the fleet's gone, or even badly hurt, what's to stop our good friends over yonder landing two or three million men just anywhere they choose, and doing pretty well what they like afterwards? By the Saints, that would be a horrible thing. We've nothing on land that could stand against them, though, of course, the boys would stand till they fell down; but fall they would."

"Yes," said Erskine, seriously. "It wouldn't exactly be a walk over for them, but I'm afraid there couldn't be very much doubt at the end, if the fleet once went."

"I'm afraid not," replied Castellan, "and we can only hope that our Lords of the Council will be of the same opinion, or, better still, that the infernal thing we saw belongs to us."

"I hope so," said Erskine, gravely. "If it doesn't—well, I wouldn't give half-a-crown for the biggest battleship in the British Navy."