"A rather well known gentleman," Cowan replied, tantalizingly. "Both of you are quite well acquainted with Lieutenant Siddons, I believe?"

Larkin looked at McGee in astonishment.

"No, sir," McGee replied to Cowan, "no one in this outfit knows that fellow very well."

"Quite right," Cowan agreed. "Lieutenant Larkin, I recall that you lost your old R.F.C. uniform a good while back."

"Yes, sir."

"And in the pocket was your old identification fold, and certain other papers? An old pa.s.s to Paris, for one thing?"

"Why--yes, sir. The identification card was there, but I don't recall what I did with that old pa.s.s."

"It was there," Cowan told him, "and it grieves me to inform you that the uniform, and all that the pockets contained, was stolen by Lieutenant Siddons."

"What! Are you sure?"

"There is no doubt about it. Furthermore, he delivered them into the hands of the enemy." Larkin was too dumbfounded for words, but McGee displayed little surprise.

"So you have at last found out what I knew all along, Major?" Red asked.

"Not _at last_," Cowan replied, with meaning emphasis. "Your uniform, Lieutenant Larkin, will be returned to you soon--we hope."

"Oh!" McGee jerked his head toward the door. "So that's the reason for the M.P.'s. You are going to nab him?"

"Not exactly that." Cowan was enjoying the curiosity provoked by the suspense he was creating. "I believe both of you have heard of a certain German ace, Count von Herzmann?"

"_Have_ we!" Larkin replied.

McGee ran his fingers along a white scar still showing through the hair which had not yet grown out long enough to be the flaming red mop of old.

"Seems I've heard of him," he said. "And I seem to recall that one of his flyers left me this little souvenir on the top of my head. I'd like to pay the Count back--in person."

"You'll never get the chance!" Cowan replied. "But if all our plans work out, you will meet him in person soon--in this very room!"

"What!" It was a duet of surprise.

"Yes, here. Count von Herzmann in person--and in Lieutenant Larkin's long lost uniform."

Both McGee and Larkin sank weakly into two convenient chairs, the expression on their faces disclosing that they were trying to select the proper order of the first of a thousand questions.

"Well--what's that to do with--with Siddons?" McGee at last found stammering tongue. "Where does he come in?"

"He comes in a few minutes after the Count. He will land the Count in a field near here, let him alight, and then take off again and proceed to this 'drome. The Count, left alone, will doubtless make his way into the woods bordering the field, where he will promptly be nabbed. That little drama should be taking place now. For your information, the credit for this coup goes to Lieutenant Siddons."

McGee and Larkin stared at each other, scarce believing their ears.

"Well what do you know about that!" McGee's half audible remark was the trite expression so commonly used by those who are staggered by a sudden revelation.

"I know _all_ about it," Cowan said, actually laughing--the first time either of the others had ever heard him even so much as chuckle. "I know all about it, and I've called you here for two reasons: I think you, McGee, are ent.i.tled to see the next to the last act in this little--ah--tragedy, I suppose it should be called; and I want Larkin to be present when his uniform reappears. I might need him for purposes of identification."

"But--"

Cowan lifted a protesting hand. "Don't ask questions. Better let me tell it. The story will have to be brief, and a bit sketchy, for time flies.

The things you don't know about all this would fill a book. Perhaps I had better start at the beginning:

"In 1914, when the war first broke out, the man you know as Siddons was living in Germany, with his father and mother, and was in his second year in a Berlin university. He was born in America, of German-American parents. For your information, his right name is Schwarz, not Siddons."

"I always thought he looked like a German," McGee said.

Cowan merely nodded. "Naturally, he does. His father, who had come to America in his youth to escape four years military service with the colors, developed into an exceedingly shrewd business man and had been sent back to Germany as the Berlin representative of one of our large exporters. Though he had become an American citizen, he was, quite naturally, genuinely sympathetic with Germany as against England and France. But when it began to be almost a certainty that America would be drawn into the war, the Schwarz family held a family conference and the old man declared himself as being loyal to America, his adopted country, if war actually came.

"During the months of strained relationship between our country and Germany, the Schwarz family had to keep their mouths shut and saw wood.

Then, suddenly, America declared war. Many Americans, and German-Americans, were caught in Germany. This was the case of the Schwarz family. The old gentleman was arrested, in fact, and the military authorities claimed that since he had never served with the colors he was subject to their orders.

"Then young Schwarz--the man you know as Siddons--saw a chance to relieve the pressure and at the same time serve America in a most unusual way, a way not possible with one man in a million."

"Serve America? You mean Germany?" Larkin interjected.

"I said America," Cowan replied testily. He did not like to be interrupted. "You'd better let me tell it my way. As I was saying, Siddons, claiming to be in complete sympathy with the German cause, offered his services to them as a secret agent, unfolding a plan which they, in their alarm and need, swallowed--hook, line and sinker.

"The plan was this: He proposed that he be given instruction in secret service work and then be returned to America, where he would pose as a loyal American, get in the army, and serve as an under cover man for Germany. They fell for it like a ton of brick, following the stupid reasoning that because of his German blood he must by nature be truly German. It may sound funny to you, but they preach that very thing, and they truly believe it.

"Well, certainly young Schwarz was cast perfectly for the role. He was widely travelled, spoke German fluently, and his English was flawless.

They were quick to see the advantages. His proposition was accepted. He was given a brief schooling in their spy system, and then, for show, he was ordered out of Germany--under the fict.i.tious name of Siddons.

"The rest was easy. We had a very poor spy system at the beginning of the war. There was no such branch of service as we now call G 2. But it was forming, and to them Schwarz made his way, unfolded his plan, and after a careful checking up on his story they decided to take a chance.

A spy within a spy! Wheels within wheels! It was a great idea. Do you see it?"

His two auditors made no sign other than a staring, amazed look.

"G 2 was at first suspicious," Cowan went on, "but he gave them so much information concerning actual conditions in Germany that they could no longer doubt him. They sent him to an aviation training school, telling him to guard his neck at all times and not run any undue risks.

"You know the rest--or most of it. He has been invaluable to us, and to-night he will pull his greatest job. And since I have made free to tell you all this, you may be certain it is his last trip across the lines. He reports that the German High Command is getting a bit suspicious, and he dare not trust his luck much further."

McGee, who had been listening with intense interest, exhaled audibly as Cowan finished his narration. "Well!" he exclaimed. "I'll never jump to conclusions again. Now I know why that fellow has always acted like he was answerable to no one but himself. And I thought him yellow! And next I thought he was a spy. Well, I was right about that--but the wrong way around. I take my hat off to him! It takes nerve to fill his job."

"It does indeed!" Cowan agreed fervently. "Perhaps you recall how I bawled him out for cutting formation over Vitry that day when we were on our way up for our first action? And how I sent him over the lines on a mission to locate von Herzmann's Circus?"

McGee nodded. "I certainly do remember it. You sure said plenty!"

"Hok.u.m! All hok.u.m!" Cowan said. "Actually, he was going over on a daylight mission of an entirely different nature, and what I said in your presence was merely to mislead you. Unfortunately, you happened to see him running the Archie fire and saw the signals which he had used again and again in crossing over. When you reported to me, we feared the cat was out of the bag. There seemed to be only one way out--to pledge you to secrecy and lead you to believe that we were simply waiting for the proper time to bag him. I knew you would keep your word, and that is another reason why you are here--as a sort of reward. You are the only one who has ever had any such suspicions."

Larkin laughed, mirthlessly. "That makes a lot of chuckle-heads out of the rest of us, doesn't it?"

"Oh, I wouldn't say that, Lieutenant. But you did make life rather hard for Siddons. He was afraid to form close friendships. Poor Hampden was the only one he was ever very close to, and Hampden was as ignorant of the facts as any of you. Siddons had to be careful. He knows that the Germans also have spies. Should they get proof of his duplicity, he would be a doomed man."

"Well," McGee sighed again, "he can have my share of that kind of service. I prefer to meet mine without any blindfold over my eyes. I'll make my apologies to him, and admit to his face that he has more nerve than most men I know. But there is one thing I can't get through my head, Major. How could he keep fooling them if he never took them any information?"