When at last I arrived at Cary's flat it was very late, and I was exceedingly tired and out of temper. A squadron of Zeppelins had been reported from the sea, the air-defence control at Newcastle had sent out the preliminary warning "F.M.W.," and the speed of my train had been reduced to about fifteen miles an hour. I had expected to get in to dinner, but it was eleven o'clock before I reached my destination. I had not even the satisfaction of seeing a raid, for the Zepps, made cautious by recent heavy losses, had turned back before crossing the line of the coast. Cary and his wife fell upon my neck, for we were old friends, condoled with me, fed me, and prescribed a tall glass of mulled port flavoured with cloves. My stern views upon the need for Prohibition in time of war became lamentably weakened.

By midnight I had recovered my philosophic outlook upon life, and Cary began to enlighten me upon the details of the grave problem which had brought me eagerly curious to his city.

"I expect that Dawson will drop in some time to-night," he said. "All hours are the same to him. I told him that you were on the way, and he wants to give you the latest news himself. He is dead set upon you, Copplestone. I can't imagine why."

"Am I then so very unattractive?" I inquired drily. "It seems to me that Dawson is a man of sound judgment."

"I confess that I do not understand why he lavishes so much attention upon you."

"Your remarks, Cary," I observed, "are deficient in tact. You might, at least, pretend to believe that my personal charm has won for me Dawson's affection. As a matter of fact, he cares not a straw for my beaux yeux; his motives are crudely selfish. He thinks that it is in my power to contribute to the greater glory of Dawson, and he cultivates me just as he would one of his show chrysanthemums. He has done me the honour to appoint me his biographer extraordinary."

"I am sure you are wrong," cried Cary. "He was most frightfully angry about that story of ours in Cornhill. He demanded from me your name and address, and swore that if I ever again disclosed to you official secrets he would proceed against me under the Defence of the Realm Act. He was a perfect terror, I can assure you."

"And yet he always carries that story about with him in his breast-pocket; he has summoned me here to see him at his work; and you have been commanded to tell me everything which you know! My dear Cary, do not be an ass. You are too simple a soul for this rather grubby world. In your eyes every politician is an ardent, disinterested patriot, and every soldier or sailor a knightly hero of romance. Human beings, Cary, are made in streaks, like bacon; we have our fat streaks and our lean ones; we can be big and bold, and also very small and mean. Your great man and your national hero can become very poor worms when, so to speak, they are off duty. But I didn't come here, at great inconvenience, to talk this sort of stuff at midnight. Go ahead; give me the details of this sabotage case which is baffling Dawson and the naval authorities; let me hear about the cutting of those electric wires."

"It is, as I told you, in my note, a queer business. The Antinous, a fast light cruiser, came in about a fortnight ago to have some defects made good in her high-speed geared-turbines. There was not much wrong, but her engineer commander recommended a renewal of some of the spur wheels. The officers and crew went on short leave in rotation, a care and maintenance party was put in charge, and the builders placed a working gang on board which was occupied in shifts, by night and by day, in making good the defects. When a ship is under repair in a river basin, it is practically impossible to keep up the beautiful order and discipline of a ship at sea. Men of all kinds are constantly coming and going, life on board is stripped of the most ordinary comforts and conveniences, there is inevitably some falling off in strict supervision. Lack of space, lack of facilities for moving about the ship, lack of any regular routine. You will understand. Just as the expansion in the New Army and the New Navy has made it possible for unknown enemy agents to take service in the Army and the Navy, so the dilution of labour in the shipyards has made it possible for workmen—whose sympathies are with the enemy—to get employment about the warships. The danger is fully recognised, and that is where Dawson's widespread system of counter-espionage comes in. There is not a trade union, among all the eighteen or twenty engaged in shipyard work—riveters, fitters, platers, joiners, and all the rest of them—in which he has not police officers enrolled as skilled tradesmen, members of the unions, working as ordinary hands or as foremen, sometimes even in office as "shop stewards" representing the interest of the unions and acting as their spokesmen in disputes with the employers. Dawson claims that there has never yet been a secret Strike Committee, since the war began, upon which at least one of his own men was not serving. He is a wonderful man. I don't like him; he is too unscrupulous and merciless for my simple tastes; but his value to the country is beyond payment."

"But where in the world does he raise these men? One can't turn a policeman into a skilled worker at a moment's notice. How is it done?"

"He begins at the other end. All his skilled workmen are the best he can pick out of their various trades. They have served their full time as apprentices and journeymen. They are recommended to him by their employers after careful testing and sounding. Most of them, I believe, come from the Government dockyards and ordnance factories. They are given a course of police training at Scotland Yard, and then dropped down wherever they may be wanted. Dawson, and inspectors like him, have these men everywhere—in shipyards, in shell shops, in gun factories, in aeroplane sheds, everywhere. They take a leading part in the councils of the unions wherever they go, for they add to their skill as workmen a pronounced, even blatant parade of loyalty to the interests of trade unions and a tasty flavour of socialist principles. Dawson is perfectly cynically outspoken to me over the business which, I confess, appals me. In his female agents—of which he has many—he favours what he calls a 'judicious frailty'; in his male agents he favours a subtle skill in the verbal technique of anarchism. And this man Dawson is by religion a Peculiar Baptist, in private life a faithful husband and a loving father, and in politics a strict Liberal of the Manchester School! As a man he is good, honest, and rather narrow; as a professional detective he is base and mean, utterly without scruple, and a Jesuit of Jesuits. With him the end justifies the means, whatever the means may be."

"And yet you admit that his value to the country is beyond payment. Dawson—our remarkable Dawson of the double life in the two compartments, professional and private, which never are allowed to overlap—Dawson is an instrument of war. We do not like using gas or liquid fire, but we are compelled to use them. We do not like espionage, but we must employ it. As one who loves this fair land of England beyond everything in the world, and as one who would do anything, risk anything, and suffer anything to shield her from the filthy Germans, I rejoice that she has in her service such supremely efficient guardians as this most wickedly unscrupulous Dawson. There is, at any rate, not a trace of our English muddle about him."

"Ours is a righteous cause," cried poor Cary desperately. "We are fighting for right against wrong, for defence against aggression, for civilisation against utter barbarism. We are by instinct clean fighters. If in the stress of conflict we stoop to foul methods, can we ever wash away the filth of them from our souls? We shall stand before the world nakedly confessed as the nation of hypocrites we have always been declared to be."

"Cary," I said, "you make me tired. We cannot be too thankful that we possess Dawsons to counterplot against the Germans, and that personally we are in no way responsible for the morality of their methods. Come off the roof and get back to this most interesting affair of the Antinous. I presume one of Dawson's men was working, unknown to his fellows, with the care and maintenance party, and another, equally unknown, with the engineers who were busy upon the gearing of the turbines. Many of the regular ship's officers and men would also have been on board. Had our remarkable friend his agents among them too? Everything is possible with Dawson; I should not be surprised to hear that he had police officers in the Fleet flagship."

"You are almost right. One of his men, a temporary petty officer of R.N.V.R., was certainly on board, and he tells me that down in the engine room was another—a civilian fitter. They were both first-class men. The electric wires, as you know, are carried about the ship under the deck beams, where they are accessible for examination and repairs. They are coiled in cables from which wires are led to the switch room, and thence to all parts of the ship. There are thousands of wires, and no one who did not know intimately their purpose and disposition could venture to tamper with them, for great numbers are always in use. If any one cut the lighting wires, for instance, the defects would be obvious at once; so with the heating or telephone wires. Nothing was touched except the lines to the guns, of which there are eight disposed upon the deck. From the guns connections run to the switch room, the conning tower, the gunnery control platform aloft, and to the gunnery officer's bridge. It was the main cable between the switch room and the conning tower which was cut, and it was one cable laid alongside a dozen others. Now who could know that this was the gun cable, and the only one in which damage might escape detection while the ship was in harbour? At sea there is constant gun drill, during which the electrical controls and the firing-tubes are always tested, but in harbour the guns are lying idle most of the time. It was evidently the intention of the enemy, who cut these wires, that the Antinous should go to sea before the defect was discovered, and that her fire control should be out of action till the wiring system could be repaired. That very serious disaster was prevented by the preliminary testing during the night before sailing, but the enemy has been successful in delaying the departure of an invaluable light cruiser for two days. In these days, when the war of observation is more important even than the war of fighting, the services of light cruisers cannot be dispensed with for an hour without grave inconvenience and risk. Yet here was one delayed for forty-eight hours after her ordinary repairs had been completed. The naval authorities are in a frightful stew. For what has happened to the Antinous may happen to other cruisers, even to battleships. If there is sabotage among the workmen in the shipyards, it must be discovered and stamped out without a moment's delay. This time it is the cutting of a wire cable; at another time it may be some wilful injury far more serious. A warship is a mass of delicate machinery to which a highly skilled enemy agent might do almost infinite damage. Dawson has been run off his feet during the past two days; I don't know what he has discovered; but if he does not get to the bottom of the business in double-quick time we shall have the whole Board of Admiralty, Scotland Yard, and possibly the War Cabinet down upon us. Think, too, of the disgrace to this shipbuilding city of which we are all so proud."

"We shall know something soon," I said, "for, if I mistake not, here comes Dawson." The electric bell at the front door had buzzed, and Cary, slipping from the room, presently returned with a man who to me, at the first glance, was a complete stranger. I sprang up, moved round to a position whence I could see clearly the visitor's ears, and gasped. It was Dawson beyond a doubt, but it was not the Dawson whom I had known in the north. So what I had vaguely surmised was true—Cary's Dawson and Copplestone's Dawson were utterly unlike. Dawson winked at me, glanced towards Cary, and shook his head; from which I gathered that he did not desire his appearance to be the subject of comment. I therefore greeted him without remark, and, as he sat down under the electric lights, examined him in detail. This Dawson was ten years older than the man whom I had known and fenced with. The hair of this one was lank and grey, while that of mine was brown and curly; the face of this one was white and thin, while the face of mine was rather full and ruddy. The teeth were different—I found out afterwards that Dawson, who had few teeth of his own, possessed several artificial sets of varied patterns—the shape of the mouth was different, the nose was different. I could never have recognised the man before me had I not possessed that clue to identity furnished by his unchanging ears.

"So, Dawson," said I slowly, "we meet again. Permit me to say that I congratulate you. It is very well done."

He grinned and glanced at the unconscious Cary. "You are learning.
Bill Dawson takes a bit of knowing."

"Have you any news, Mr. Dawson?" asked Cary eagerly.

"Not much. The wires of the Antinous have all been renewed—the Admiralty won't allow cables to be patched except at sea—but I haven't found out who played hanky-panky with them. It could not have been any one in the engine-room party, as none of them went near the place where the wires were cut. Besides, they were engineers, not electricians, and could have known nothing of the arrangements and disposition of the ship's wires. My man who worked with them is positive that they are a sound, good lot without a sea-lawyer or a pacifist among them; a gang of plain, honest tykes. So we are thrown back on the maintenance party, included in which were all sorts of ratings. Some of them are skilled in the electrical fittings—my own man with them is, for one—but we get the best accounts of all of them. They are long service men, cast for sea owing to various medical reasons, but perfectly efficient for harbour work. Among the officers of the ship is a R.N.R. lieutenant with a German name. I jumped to him, but the captain laughed. The man's father and grandfather were in the English merchant service, and though his people originally came from Saxony, he is no more German than we are ourselves. Besides, my experience is that an Englishman with an inherited German name is the very last man to have any truck with the enemy. He is too much ashamed of his forbears for one thing; and for another he is too dead set on living down his beastly name. So we will rule out the Lieutenant R.N.R. My own man, who is a petty officer R.N.V.R., and has worked on a lot of ships which have come in for repairs, says that the temper among the workmen in the yards is good now. It was ugly when dilution of labour first came in, but the wages are so high that all that trouble has settled down. I have had what you call sabotage in the shell and gun shops, but never yet in the King's ships. We have had every possible cutter of the wires on the mat before the Captain and me. We have looked into all their records, had their homes visited and their people questioned, inquired of their habits—Mr. Copplestone, here, knows what comes of drink—and found out how they spend their wages. Yet we have discovered nothing. It is the worst puzzle that I've struck. When and how the gun cable was cut I can't tell you, but whoever did it is much too clever to be about. He must have been exactly informed of the lie and use of the cables, had with him the proper tools, and used them in some fraction of a minute when he wasn't under the eye of my own man whose business it was to watch everybody and suspect everybody. I thought that I had schemed out a pretty thorough system; up to now it has worked fine. Whenever we have had the slightest reason to suspect any man, we have had him kept off the ship and watched. We have run down a lot of footling spies, too stupid to give us a minute's anxiety, but this man who cut the Antinous's wires is of a different calibre altogether. He is AI, and when I catch him, as I certainly shall, I will take off my hat to him."

"You say that the Antinous is all right now?" I observed.

"Yes. I saw her towed out of the repair basin an hour ago, and she must be away down the river by this time. It is not of her that I'm thinking, but of the other ships which are constantly in and out for repairs. There are always a dozen here of various craft, usually small stuff. While the man who cut those wires is unknown I shall be in a perfect fever, and so will the Admiral-Superintendent. We'll get the beauty sooner or later, but if it is later, there may be had mischief done. If he can cut wires in one ship, he may do much worse things in some other. The responsibility rests on me, and it is rather crushing."

Dawson spoke with less than his usual cheery confidence. I fancy that the thinness and whiteness of his face were not wholly due to disguise. He had not been to bed since he had been called up in the middle watch of the night before last, and the man was worn out.

"If you take my poor advice, Dawson," I said, "you will cut off now and get some sleep. Even your brain cannot work continuously without rest. The country needs you at your best, and needs you very badly indeed."

His dull, weary eyes lighted as if under the stimulus of champagne, and he turned upon me a look which was almost affectionate. I really began to believe that Dawson likes me, that he sees in me a kindred spirit as patriotically unscrupulous as himself.

He jumped up and gripped my hand. "You are right. I will put in a few hours' sleep and then to work once more. This time I am up against a man who is nearly as smart as I am myself, and I can't afford to carry any handicap."

I led him to the door and put him out, and then turned to Cary with a laugh. "And I, too, will follow Dawson's example. It is past one, and my head is buzzing with queer ideas. Perhaps, after all, the Germans have more imagination than we usually credit them with. I wonder—" But I did not tell to Cary what I wondered.

* * * * *

We were sitting after breakfast in Cary's study, enjoying the first sweet pipe of the day, when the telephone bell rang. Cary took off the earpiece and I listened to a one-sided conversation somewhat as follows:—

"What! Is that you, Mr. Dawson? Yes, Copplestone is here. The Antigone? What about her? She is a sister ship of the Antinous, and was in with damage to her forefoot, which had been ripped up when she ran down that big German submarine north of the Orkneys—Yes, I know; she was due to go out some time to-day. What do you say? Wires cut? Whose wires have been cut? The Antigone's? Oh, the devil! Yes, we will both come down to your office this afternoon. Whenever you like."

Cary hung up the receiver and glared at me. "It has happened again," he groaned. "The Antigone this time. She has been in dry dock for the past fortnight and was floated out yesterday. Her full complement joined her last night. Dawson says that he was called up at eight-o'clock by the news that her gun-wires have been cut exactly like those of the Antinous and in the same incomprehensible way. He seems, curiously enough, to be quite cheerful about it."

"He has had a few hours sleep. And, besides, he sees that this second case, so exactly like the first, makes the solution of his problem very much more easy. I am glad that he is cheerful, for I feel exuberantly happy myself. I was kept awake half the night by a persistent notion which seemed the more idiotic the more I thought all round it. But now—now, there may be something in it."

"What is your idea? Tell me quick."

"No, thank you, Dr. Watson. We amateur masters of intuition don't work our thrilling effects in that way. We keep our notions to ourselves until they turn out to be right, and then we declare that we saw through the problem from the first. When we have been wrong, we say nothing. So you observe, Cary, that whatever happens our reputations do not suffer."