"Wait a moment and hear me out," the Chief went on. "What is required for this job is a man of great courage and steady nerve.

Yes, we have plenty of fellows like that. But the man I am looking for must, in addition to possessing those qualities, know German and the Germans thoroughly, and when I say thoroughly I mean to the very core so that, if needs be, he may be a German, think German, act German. I have men in my service who know German perfectly and can get themselves up to look the part to the life. But they have never been put to the real, the searching test. Not one of them has done what you and your brother successfully accomplished. The first time I came across you, you had just come out of Germany after fetching your brother away. To have lived for weeks in Germany in wartime and to have got clear away is a feat which shows that both you and he can be trusted to make a success of one of the most difficult and critical missions I have ever had to propose. Francis is not here. That's why I want you."

The Chief paused as if weighing something in his mind.

"It's not the custom of either service, Okewood," he said, "to send a man to certain death. You're not in this creepy, crawly business of ours. You're a pukka soldier and keen on your job. So I want you to know that you are free to turn down this offer of mine here and now, and go back to France without my thinking a bit the worse of you."

"Would you tell me something about it?" asked Desmond.

"I'm sorry I can't," replied the other. "There must be only two men in this secret, myself and the fellow who undertakes the mission. Of course, it's not certain death. If you take this thing on, you'll have a sporting chance for your life, but that's all. It's going to be a desperate game played against a desperate opponent. Now do you understand why I didn't want you to think I was flattering you? You've got your head screwed on right, I know, but I should hate to feel afterwards, if anything went wrong, that you thought I had b.u.t.tered you up in order to entice you into taking the job on!"

Desmond took two or three deep puffs of his cigarette and dropped it into the ash-tray.

"I'll see you!" he said.

The Chief grinned with delight.

"By Jove!" he exclaimed, "I knew you were my man!"

CHAPTER VII. NUR-EL-DIN

The love of romance is merely the n.o.bler form of curiosity. And there was something in Desmond Okewood's Anglo-Irish parentage that made him fiercely inquisitive after adventure. In him two men were constantly warring, the Irishman, eager for romance yet too indolent to go out in search of it, and the Englishman, cautious yet intensely vital withal, courting danger for danger's sake.

All his ill-humor of the morning at being s.n.a.t.c.hed away from his work in France had evaporated. In the Chief he now saw only the magician who was about to unlock to him the realms of Adventure.

Desmond's eyes shone with excitement as the other, obviously simmering with satisfaction, lit another cigarette and began to speak.

"The British public, Okewood," he said, hitching his chair closer, "would like to see espionage in this country rendered impossible. Such an ideal state of things is, unfortunately out of the question. Quite on the contrary, this country of ours is honeycombed with spies. So it will ever be, as long as we have to work with natural means: at present we have no caps of invisibility or magician's carpets available.

"As we cannot hope to kill the danger, we do our best to scotch it. Personally, my modest ambition is to make espionage as difficult as possible for the enemy by knowing as many as possible of his agents and their channels of communication, and by keeping him happy with small results, to prevent him from finding out the really important things, the disclosure of which would inevitably compromise our national safety."

He paused and Desmond nodded.

"The extent of our business," the Chief resumed, "is so large, the issues at stake so vital, that we at the top have to ignore the non-essentials and stick to the essentials. By the nonessentials I mean the little potty spies, actuated by sheer hunger or mere officiousness, the neutral busybody who makes a tip-and-run dash into England, the starving waiter, miserably underpaid by some thieving rogue in a neutral country--or the frank swindler who sends back to the Fatherland and is duly paid for long reports about British naval movements which he has concocted without setting foot outside his Bloomsbury lodgings.

"These folk are dealt with somehow and every now and then one of 'em gets shot, just to show that we aren't asleep, don't you know? But spasmodic reports we can afford to ignore. What we are death on is anything like a regular news service from this country to Germany; and to keep up this steady flow of reliable information is the perpetual striving of the men who run the German Secret Service.

"These fellows, my dear Okewood, move in darkness. Very often we have to grope after 'em in darkness, too. They don't get shot, or hardly ever; they are far too clever for that. Between us and them it is a never-ending series of move and countermove, check and counter-check. Very often we only know of their activities by enemy action based on their reports. Then there is another leak to be caulked, another rat-hole to be nailed up, and so the game goes on. Hitherto I think I may say we have managed to hold our own!"

The Chief stopped to light another cigarette. Then he resumed but in a lower voice.

"During the past month, Okewood," he said, "a new organization has cropped up. The objective of every spy operating in this country is, as you may have surmised, naval matters, the movements of the Fleet, the military transports, and the food convoys. This new organization has proved itself more efficient than any of its predecessors. It specializes in the movement of troops to France, and in the journeys of the hospital ships across the Channel. Its information is very prompt and extremely accurate, as we know too well. There have been some very disquieting incidents in which, for once in a way, luck has been on our side, but as long as this gang can work in the dark there is the danger of a grave catastrophe. With its thousands of miles of sea to patrol, the Navy has to take a chance sometimes, you know! Well, on two occasions lately, when chances were taken, the Hun knew we were taking a chance, and what is more, when and where we were taking it!"

The Chief broke off, then looking Desmond squarely in the eyes, said:

"This is the organization that you're going to beak up!"

Desmond raised his eyebrows.

"Who is at the head of it?" he asked quietly.

The Chief, smiled a little bitterly.

"By George!" he cried, slapping his thigh, "you've rung the bell in one. Okewood, I'm not a rich man, but I would gladly give a year's pay to be able to answer that question. To be perfectly frank with you, I don't know who is at the back of this crowd, but..." his mouth set in a grim line, "I'm going to know!"

He added whimsically:

"What's more, you're going to find out for me!"

Desmond smiled at the note of a.s.surance in his voice.

"I suppose you've got something to go on?" he asked. "There's Nur-el-Din, for instance. What about her?"

"That young person," replied the Chief, "is to be your particular study. If she is not the center of the whole conspiracy, she is, at any rate, in the thick of it. It will be part of your job to ascertain the exact role she is playing."

"But what is there against her?" queried Desmond.

"What is there against her? The bad company she keeps is against her. 'Tell me who your friends are and I'll tell you who you are'

is a maxim that we have to go on in our profession, Okewood. You have met the lady. Did you see any of her entourage? Her business manager, a fat Italian who calls himself Lazarro, did you notice him? Would you be surprised to hear that Lazarro alias Sacchetti alias Le Tardenois is a very notorious international spy who after working in the Italian Secret Service in the pay of the Germans was unmasked and kicked out of Italy... that was before the war? This pleasant gentleman subsequently did five years in the French penal settlements in New Caledonia for robbery with violence at Aix-les-Bains... oh, we know a whole lot about him!

And this woman's other friends! Do you know, for instance, where she often spends the week-end? At the country-place of one Bryan Mowbury, whose name used to be Bernhard Marburg, a very old hand indeed in the German Secret Service. She has identified herself right and left with the German espionage service in this country.

One day she lunches with a woman spy, whose lover was caught and shot by the French. Then she goes out motoring with..."

"But why in Heaven's name are all these people allowed to run loose?" broke in Desmond. "Do you mean to say you can't arrest them?"

"Arrest 'em? Arrest 'em? Of course, we can arrest 'em. But what's the use? They're all small fry, and we have to keep out a few lines baited with minnows to catch the Tritons. None of 'em can do any harm: we watch 'em much too closely for that. Once you've located your spy, the battle's won. It's when he--or it may be a she--is running loose, that I get peeved!"

The Chief sprang impatiently to his feet and strode across the smoking-room, which was all but empty by this time, to get a match from a table. He resumed his seat with a grunt of exasperation.

"I can't see light, Okewood!" he sighed, shaking his head.

"But is this all you've got against Nur-el-Din?" asked Desmond.

"No," answered the other slowly, "it isn't. If it were, I need not have called you in. We would have interned or deported her.

No, we've traced back to her a line leading straight from the only member of the new organization we have been able to lay by the heels."

"Then you've made an arrest?"

The Chief nodded.

"A fortnight ago... a respectable, retired English business man, by name of Basil Bellward... taken with the goods on him, as the saying is..."

"An Englishman, by Jove!"

"It's hardly correct to call him an Englishman, though he's posed as an English business man for so long that one is almost justified in doing so. As a matter of fact, the fellow is a German named Wolfgang Bruhl and it is my belief that he was planted in this country at least a dozen years ago solely for the purpose of furnishing him with good, respectable credentials for an emergency like this."

"But surely if you found evidence of his connection with this gang of spies, it should be easy to get a clue to the rest of the crowd?"

"Not so easy as you think," the Chief replied. "The man who organized this system of espionage is a master at his craft. He has been careful to seal both ends of every connection, that is to say, though we found evidence of Master Bellward-Bruhl being in possession of highly confidential information relating to the movements of troops, we discovered nothing to show whence he received it or how or where he was going to forward it. But we did find a direct thread leading straight back to Nur-el-Din."