Singleton stood there in the middle of the hall, facing the open door, and still, as though he had the smallest right to touch anything of hers, he held Miss Anne Ellis's letter in his hand.

"Something must have happened to Sir William," he said.

"Puncture," suggested Napier, all his energies concentrated for the moment on suppressing every outward sign of concern about the fate of the letter. He had forced his eyes away from it. Yet, wherever he looked, he was more aware of that white square in Singleton's hands than of anything else in the hall.

But Napier had pulled himself together with a strong hand. He mustn't lose an instant; he shied away from formulating even in secret the idea of which Singleton's mind must be disabused. He got only as far as to ask himself, with a ghastly inner sinking, just what danger was there—could there conceivably be—of Nan's being inadvertently caught in the net he, Gavan Napier, had helped to spread? Nan! He leaned hard against the table. Of course—he told himself—of course, they'd find nothing, nothing in the world to implicate Nan. But the shock, the wound! How she'd loathe this England! He sat down heavily.

Singleton came sauntering back, the long chin in one hand, the overbrilliant eyes on Napier. To make an enemy of this man, in the present universal instability of equilibrium, wouldn't it be a stupid as well as dangerous mistake?

"Smoke?" suggested Napier. He felt for his cigar case.

Singleton didn't mind if he did. As he sat down on the other side of the table, he dropped Miss Ellis's letter on the pile.

Oh, but the letter looked well on the table! It suddenly occurred to Napier, lightly slapping his pockets—what had he done with those cigars?—there was something not only attractive about Singleton, but downright likeable.

"It must be a curious life, yours," he said.

"Well, you know how it is yourself."

"I know?" It was one thing to leave off hating him, quite another to ally Gavan Napier with the underground work of the world of spies.

"Nous pÊchons aujourd'hui des plus gros poissons, surtout À,"—he dropped out as lightly as a smoke-ring the final words, "Gull Island."

Napier, leaning forward to take back the burning match, very nearly fell off his chair.

"What do you know about—"

"Oh, Gull Island is one of our secret-service pets," Singleton went on, still in French—though it seemed the height of improbability that, had he spoken in English, any unseen listener could have distinguished words falling in the voice you would say was low by nature rather than by caution. "Jolly little place, Gull Island. I was there last month."

"Comment!" Napier said, accepting the medium chosen by his interlocutor. "You mean before I—"

"Oh, yes, two weeks before you reported. You didn't, so far as I remember,"—he seemed to indicate a flaw or even a suspicious circumstance—"you didn't connect this woman with it."

"What woman?"

"Oh, then there is more than one?"

"Oh, see here,"—Napier's patience, perhaps even his self-control, was wearing thin—"what's the use of going on like this? You know there's only one suspicious person hereabouts. What you couldn't know is that I wrote from Scotland a full and complete statement."

"Who to?"

"To Sir William!"

"That was before you were warned?"

"Warned?"

"To keep the Gull Island business to yourself."

Before Napier could bring out his slightly annoyed defense, Singleton went on: "I wouldn't have dreamed of broaching the matter, if I hadn't just got my instructions to meet you in London for the express purpose of telling you that the importance of Gull Island isn't a thing of the past." He waited while Napier digested the news in a wondering silence.

"In your report to headquarters you didn't, I gather, mention the lady," Singleton persisted.

"Why should I? So far as she was concerned I had only my unsupported suspicions to go on. I thought it only fair to Sir William to leave the initiative there to him."

"I see. It was perhaps the more convenient thing to do."

"It wasn't at all convenient," Napier assured him with asperity. "I got into such particularly hot water over my case against the lady that I don't at this moment know whether I am still private secretary to Sir William McIntyre or not."

"Why is that?"

"She persuaded him that I was, to put it mildly, salving my wounded feelings. Oh, she's—" Napier jumped up, and went to the door.

"Yes, she is," Singleton's voice sounded an amused agreement.

"What is she?" Napier demanded, turning round. "Does anybody know?"

"Well, what do you think we're for?"

Napier stood there, an embodied interrogation. How closely did it touch Nan Ellis, the knowledge this man had?

"We've kept an eye on her for some time. She has been unconsciously—" Singleton flicked his cigar-ash—"of considerable use to us. Oh, she's well known. Devils for Pforzheim and Engleberg."

"Engleberg? Who is Engleberg?"

"The older one, who called himself Carl Pforzheim. A slim pair, those two!"

"He got away?"

Singleton smiled. "One got away—Carl. Ernst is—extremely safe."

The thought of Lady McIntyre came to Napier, along with the horror of the picture Singleton had evoked; intimates of Kirklamont, donors of Boris and Ivan; Mr. Ernst, in prison waiting for the firing squad; Mr. Carl showing his "nice teeth" in a rictus of terror before turning to take McClintock's knife in his throat.

"There's no call to make a mystery of this little Schwarzenberg affair," Singleton was saying. "The woman is better known in Brussels. Better known still in Cincinnati, Ohio." Singleton smiled. "She has a great reputation in a certain suburb of that semi-German city. The good people of New Bonn are proud of her. She has come on so."

"Come on?"

"Oh, she began to 'come on' from the moment she arrived, twenty years ago, at the age of twelve."

"You don't mean she's thirty-two?"

"Thirty-three, to be exact. She came from a suburb of Berlin with an older sister, to help in the patriarchal family of the Cincinnati uncle and aunt."

"The millionaire uncle?"

Singleton's nod of pleasant indulgence accompanied the more exact information.

"He'd laid by money enough to start a little beer garden. The older sister soon went out to service. This one insisted on going to school. But she helped in the beer garden between whiles. Made a friend of one of the habituÉs, a fiddler in the local band. She sang for the beer garden customers, and they threw her dimes. At fourteen she got an engagement at the little German theater. She sent home the passage money for a brother. Instead of putting him to a trade, she put him to school. This girl of fifteen. The next year she sent for another brother. MÊme jeu. Oh, she's been very decent to her family. But the voice of great souls appears always to have been Miss Schwarz's undoing. Her voice was unformed. She forced it. Broke it. At eighteen an end to hopes of great operatic career. A year or so later she went on the stage. Played in German a couple of seasons. Graduated into English. Then there's a goodish interval which we haven't yet filled. Nearly six years, I make it. When she next comes to the surface, she had fallen in with Pforzheim at Washington, and was falling out with him in Paris. The Brussels' Secret Service had employed him on that Duc de Berry case. She did the work. Pforzheim, as usual, got the credit, and naturally most of the cash. She needs an awful lot to keep her going—this woman. They quarreled over the amount. She washed her hands of the job and of him, and back she goes to America. Out of the glare and excitement of Paris and a partnership in Pforzheim's plottings, to—what do you suppose? To teach music, of all things! In San Francisco, of all places! In a private family!" Singleton laughed. "These Ellises!" He nodded at Miss Anne's letters. "Again and again we've traced Greta Schwarz doing this and that for the International Bureau, being successful and well paid, and suddenly chucking the whole thing and going back to respectability and dullness. An inversion of the desire of the moth for the flame. The desire of the butterfly to labor, to store honey and esteem!"

Napier brought him back to the point. "Now that you've landed Pforzheim, any more use for her?"

"None on earth."

"But if in this case she's been only Pforzheim's tool, is the evidence enough—?"

Singleton nodded.

"Her neck's in the noose. You don't believe her neck's in the noose?"

The smile was ugly. It gave a certain sportsman's pleasure to Napier's reply.

"She's a very clever person—is Miss von Schwarzenberg."

"Well, my experience with all these people," returned Singleton, easily, "is that the cleverest do the rashest things. Who takes care of Pforzheim's tracery of fortifications? Pforzheim? Not he. This woman, with twice his wits. And what do you think of her setting down in that idiotic diary full reports of conversations among officials? Some at dinner, some overheard. And do you think Number Eighteen—that is Pforzheim—do you think he was going to run the risk of having code messages traced to him? Not a bit of it. The compromising messages come to her."

"How do you know?"

Singleton dropped his long fingers on the orange envelope and played a brief tattoo.

"We stopped another of the same sort, signed in her name, this morning at the local post-office."

"And you could read it?"

"Anybody could read it. Order on an Amsterdam broker to buy Tarapaca nitrates."

"And what did that tell you?"

"Absolutely nothing. We've tapped messages of the same sort before."

"Then you are no forrader."

"We weren't when we got here this afternoon." Although the conversation had been carried on in low-voiced French, Singleton leaned over the table and dropped out the next sentence in a tone that barely escaped the suspicion-stirring whisper, "Grindley found a French dictionary in her writing-table."

"What good did that do you?"

"All the good in the world." Singleton's face shone with the good it did him. "You see," he went on, in that careless-sounding undertone, "the hitch was we couldn't hit on the code. That's why we've been giving her rope."

"And now?"

"Now—?" In a flash of pantomime Singleton with one hand suggested the knotting round the throat. His quick fingers carried the invisible cord above his head. He dangled the phantom felon in the air. "And the beauty of it is, she's done it herself."

"I wonder," said Napier.

"You wouldn't if you knew Grindley!" Singleton smiled comfortably as he lay back in the high carved chair. "Frightfully intelligent boy, Grindley. You see,"—suddenly he bent over the table again—"it's like this. They send about a devilish lot of their information in the form of brokers' orders. I dare say, if you've noticed, she'll pretend to read the 'Financial Times.'"

He waited only a second for the verification Napier withheld. But the familiar picture sprang up at call: Miss Greta half coquettish, half girlishly—appealing, "I must see what's happened to my poor little earnings." Sir William amused, pleasantly malicious, "As if you'd know, even if they told you! You'd far better ask me."

"Thank you immensely, but women oughtn't to be so dreadfully dependent. I'd like to make myself understand. Perhaps in time—"

And Sir William's laughter: "When rivers run uphill and kittens cry to-whitt, to-whoo!"

Singleton had taken out a note-book and scribbled two or three lines.

"She'll telegraph something like that." He held the book open on the table under Napier's eyes. "She wouldn't care a button if the post-office people gave that up or whose hands it fell into."

Certainly in Napier's hands it would have made Miss Greta no trouble.

"You might call it stupid," was his comment.

"Exactly. Nobody could be expected to see danger to the state in an order to buy Nepaul rice or Sumatra cigars. It's all right and runs on greased rails, till Grindley comes along. He turns over that La Motte of hers, till he notices some minute pencil-marks on one of the green advertisement pages at the back. The marks were so small that no eyes but Grindley's would have noticed them at all. And even Grindley couldn't read them without a magnifying glass." Singleton leaned over suddenly till he could command the avenue, stretching, sun-flecked, empty to the gates.

"Do you always hear the motor before it gets to the plantation?"

"Always."

"Well, the kind of thing that came out under the glass was: 'Market dull—Ascertain R—activity.' R," interpreted Singleton, "meaning Hosyth, of course. 'Prices falling—Leaving Southampton. Advise purchase—Report to Seventy-Six.'

"Seventy-six is the number of the German agent at Amsterdam. We've learned a good deal since we discovered that is where seventy-six hangs out. This message, for instance,"—he nodded at the one between them on the table—"says, 'Advise immediate purchase Erie at 22-1/4—3/4 and steel 129-5/8, market rising.' It's clear, according to the La Motte code, that something's got to be reported instantly to the German secret service agent at Amsterdam. The question is what? Even if we intercepted the message, we shouldn't be any the wiser. Or, rather, we shouldn't have been, if Grindley hadn't gone juggling with the numbers of the stock quotations till it occurred to him, after trying the thing twenty other ways." He stopped.

"Yes," Napier threw in. "I've been wondering why you tell me all this."

His smile was slightly abstracted.

"It's all right, I thought I heard a motor," said Singleton. He met Napier's eyes. "It's my business to know men, and before it was my business I knew you." That was the sole reference made to the Oxford episode. "Grindley's got an idea," Singleton went on and his face reflected the brilliance of it, "that the consonants in the occasional short-code words interpolated into some of the messages—words like Tubu, and so on—stand for the class of ship the submarines are to look out for. Tubu equals Torpedo boat. Kreuzer, Kleinkreuzer, Zerstorer, and so on, are indicated, we think now, in the same way."

Napier made no pretense at sharing Singleton's delight in these speculations.

"All this information," he exclaimed, "going back and forth with absolute impunity!"

"Until to-day," Singleton breathed out from full lungs. "Great day this for the service!"

But Napier sat appalled. No ship to leave our harbors, but its character and course might be known to the enemy lying in wait! He began to believe things he'd scoffed at. It was true, then, the Germans had coded in their secret-service ciphers every naval base, every ammunition center, every camp, every war-vessel of the British fleet. He said as much, with raging in his heart.

"And while ship after ship, crew after crew, goes down, what is our secret service doing!"

One member of it was blowing smoke-rings. Not till the supply of smoke gave out, did Singleton fall back on words:

"You hear very little about the English secret service, and you hear a lot about the German. That, to begin with, is an advantage, greater than you can appreciate. I don't propose to subtract from it. But there's no law against my talking about the German system. Their greatest technical flaw is that they lose themselves in a wilderness of detail. Their men will know all about the trajectory and penetration of the fourteen-inch gun, and they'll understand so little the men who make the guns that our quarrels among ourselves, our industrial unrest, is taken to mean that we're ready to consent to 'a German peace.' They'll report reams—we've seen 'em, got 'em docketed in our drawers—reams about the ordnance factories of the Argyle works. But as for the new projectile we're turning out a few hundred yards away, they'll have no more idea of that—till it goes whistling and roaring through their compact formations—than they have that the money they're still secretly supplying to Pforzheim comes straight to our Intelligence Department. All the same, where the Germans fail isn't in brains. Trouble with the ruck of 'em is, they go from the extreme of sentimentality at one end, to the extreme of brutality at the other. Pforzheim! A sort of modern Werther, with a capacity for cruelty that would turn a South Sea cannibal sick. This woman, too. Risk her own life and lose Pforzheim his, colossal business in hand, and goes on like the heroine of a shilling shocker. Can't resist collecting all the silly 'properties.' Simply dotes on the paraphernalia, pistol, and what not. One of the unwritten rules of the service: 'Make no memoranda. Carry no documents; only by rare exception carry arms.' She goes putting down compromising details, in a letter, for the amateurish pleasure of airing her 'inside knowledge' of the British Cabinet, and making use of invisible ink. No self-respecting British spy would be caught dead with most of the truck she'd collected in that box."

Napier had the very soundest conviction that, however poorly Singleton thought, or pretended to think, of Miss Greta's qualifications, he had set a guard of some sort at every possible avenue of escape. The woman was already as much a prisoner as any badger in the bottom of a bag. "If she's a specimen of the amateur," Napier said, "Heaven save us from the professional!"

Singleton laughed. "Heaven would need to look lively. I'd hate to be the custodian of damaging secrets with a fellow like Grindley about. You'll see." He struck his fist on the table. "A hundred pound sterling to a German pfennig, Grindley'll come back with that message from the Dutch agent neatly decoded. Oh, Grindley's immense!" Singleton rolled one long leg over the other, luxuriating in Grindley's immensity. "We aren't supposed to know each other—Grindley and I. But who wouldn't know Grindley! As a matter of fact, I introduced him to the chief, and the chief luckily isn't a stickler for the continental rules in this business. We English humanize it. What's the result? We totally mystify the rule-ridden Hun, and we've got the most efficient secret service in the world."

"Have we?" Napier started involuntarily at the sound of the motor turning off the high road and running now through the plantation with a muffled hum. "Here comes the—amateur!"

No acumen was required to read the fact that, in Napier's opinion, Singleton underestimated the noxious power of the amateur agent.

"I don't deny,"—the secret-service man stood up, but he dropped his voice to a lower register, as though the invisible comer were already at the door—"I'm not for a moment denying that this woman can do a certain amount of harm. She's got to be suppressed. But think of what she might do! She's had every opportunity, and she'll always fall short."

"Not ruthless enough?"

"Oh, she can be as ruthless as you please,"—Singleton for some reason had crossed the hall. He stood leaning against the wall near the billiard-room. "She could put a bullet in you nicely, after she'd blinded you with cayenne. But,"—Singleton shook his head—"she hasn't the right standards."

"Oh, standards?" echoed Napier. It seemed a queer word.

"At heart," said Singleton, "she has longings, as I read per record—ineradicable longings—for, what do you think? Respectability!" He smiled and then shook his fine head. "To be any good as a spy you must be either aristocrat—a perfectly satisfying law unto yourself, or you must be canaille. This woman—she's bourgeoise to the core, and a Romantic to boot. There doesn't exist a more fatal combination. I tell you,"—he stood erect—"Greta Schwarz is done for. Kaput!"

"She doesn't look it." Napier, leaning over, had caught sight of the car.

Gliding round the drive, the handsome occupant visibly luxuriating in the comfort and elegance of Lady McIntyre's limousine, Greta von Schwarzenberg lay back against the dove-colored cushions, with only her heightened color to show her the least stirred by the unexpected summons. Or was the color there, like a couple of flags, hung out in honor of Napier's return?

"Ecoutez!" Singleton's head appeared an instant out of the drawing-room door. "There's just one thing missing in that box of tricks upstairs—pinch of white powder. You must look out for that if we don't want a corpse on our hands."

"I must look out? See here—"

Singleton's head vanished.