Dave and Freddy didn’t say anything for a moment or two. They simply sat still and looked at the Colonel as their hearts bled in sympathy for his visible suffering. Then Dave slowly licked his lips, and put a faint sharp edge to his voice.

“That’s one way out of it, sir,” he said. “But it still wouldn’t help Uncle Sam much. Uncle Sam, and the rest of the United Nations.”

“Quite!” Freddy Farmer echoed evenly.

Colonel Welsh stiffened a little, and a hard brittle light leaped into his eyes. Then he suddenly relaxed, and one corner of his mouth went down in a faint grimace of self-reproach.

“I deserved that,” he said. “And thanks, you two. Trust you two to snap a man back to his proper mood. Among ten million other things, you’re certainly a pair of tonics. Too bad all of us can’t have you around at the same time. Seriously, though, I am in the middle of a horrible mess, the worst one I’ve ever got tangled in. And the rotten part of it is that I was so close to ironing everything out as nice as can be.”

The Colonel paused, brightened visibly and made a little waving gesture with one hand.

“But things are never as bad as they seem at first look,” he said. “Almost any minute, now, one of my agents may arrive. And then we can all get down to brass tacks and slug this thing through to a satisfactory finish.”

Dave and Freddy looked at each other. Freddy bit his lip and then nodded.

“Go ahead, Dave,” he said quietly. “He should be told, of course.”

“Told?” Colonel Welsh echoed sharply. “Told what? What now?”

“I don’t think the man you expect, sir, will arrive,” Dave said slowly. “That’s why I haven’t got my tunic. I left it spread over his face. He crashed in a P-Forty. Told us his oxygen tank had gone haywire. Thought somebody had fixed it. We spotted the crash on the way up here, in the mountains near El Prado. He—died shortly after we landed and got to him. Was his code name Copper? Did he carry this copper disc for secret identification, sir?”

As Dave ran out of breath momentarily, he took the copper disc from his pocket and handed it over. The Colonel took it as though it were a red hot coal. He dropped it on the desk top twice and had to pick it up. Suddenly he picked up the knife and dug the point into the surface of the copper and made a long scratch. Leaning way forward, Dave and Freddy saw that there was silver under the copper. The Colonel dropped the disc on the desk for the third time and looked as if he were going to collapse and come apart in chunks.

“Tell me everything,” he said in a hollow voice. “Give me all the details, every single bit you can remember. Did he say anything? Did he give you any message? Anything that sounded like a code word?”

Dave didn’t answer at once. He half closed his eyes and thought back to that scene in the mountain valley. Then slowly he related word for word everything that had taken place, and every word, or syllable of a word, that had been spoken. When he came to the end he half turned and looked at Freddy.

“Did I miss anything?” he asked. “Leave anything out?”

“Not a thing that I can recall,” the English born youth said. “I’d swear that was all of it.”

“Well, there you are, sir,” Dave said, turning to Colonel Welsh again. “If there were any code words, they must have been that Al, Bar, Cur, and Keys that he spoke. Do they mean anything to you?”

The Colonel plucked hard at his lower lip, and stared hard and savagely at the top of the desk. Finally he made noises in his throat, and shook his head.

“Nothing,” he grunted. “Those four words don’t mean anything to me. I—What’s the matter with you, Farmer?”

The last was because Freddy had suddenly sat bolt upright and was staring at one of the wall maps as though it were an ancient ghost come out of the past. He started as the Colonel spoke to him sharply. The blood rushed into his face, and he frowned in embarrassed indecision.

“Well, out with it!” Colonel Welsh snapped. “You’ve come up out of nowhere with good ideas before. What’s it now? What are you thinking about?”

Freddy Farmer hesitated a moment longer, and a look of sorrow and regret came into his face.

“Perhaps it isn’t a mystery, sir, those four words that poor chap spoke,” he said. “That chap, Rigby, spoke about receiving your wire about Copper coming up. The place he was coming from, sir. I just happened to notice it there on the map.”

“Albuquerque,” Colonel Welsh said. “Well, what about it?”

“Well—well, he had trouble forming words,” Freddy said. “Say those four words together.”

“Eh?” Colonel Welsh echoed.

“Freddy’s right!” Dave cried. “Al-bar-cur-keys! Albuquerque! It sounded to us like bar, instead of ba. And we got it keys, instead of que, pronounced key. He was trying to tell us where he’d come from, and—Yet, doggone it, I wonder?”

“Yes, Dawson?” the senior officer prompted, as Dave hesitated and fell silent. “You wonder what?”

“He repeated those four syllables several times,” the Yank born air ace replied with a frown. “And he kept saying, 'Southern.’ And he said ... 'Seven-Eleven—there.... Strike soon.’ Did he mean that this Seven-Eleven is south of Albuquerque? Or did he mean something that we haven’t got yet? And—well, is it all right to ask you about this Seven-Eleven, sir?”

Colonel Welsh didn’t reply for a couple of minutes. He seemed to go off into a thought trance. He stared at Dave and Freddy, and also right through them. He played with the gashed copper disc with his right hand, and continually clenched and unclenched his left fist.

“Yes, it’s all right for you to ask,” he finally said in a gloomy voice, “but there’s blessed little I can tell you about him. At least, blessed little that’s definite and concrete. Back in Washington my biggest Axis agent file happens to be on this Seven-Eleven. But if you want to know the truth, I have a hunch I could throw the whole confounded thing into the ash can, and I wouldn’t lose a thing of real value. In a few words, Seven-Eleven is Mystery Man Number One. He is Mystery Man X. And for the past couple of months he has been the biggest and sharpest thorn in the side of U.S. Intelligence. And for all I know right now, this Seven-Eleven may be a dozen persons, and not just one.”

Colonel Welsh paused for breath, and fell to playing with the gashed copper disc again.

“Seven-Eleven,” he continued eventually, “is only the name we’ve tacked on him. If you play dice you know that seven and eleven are the two lucky numbers. So we call him Seven-Eleven because he seems to have double luck in every single thing he does. In my file I have a report that states he was born in Germany under the name of Karl Bletz. That he came to this country shortly after the last war, and became a naturalized citizen under the name of Paul Benz. The report goes on to state that he returned to Germany in 1933 and hooked up with Hitler’s movement. He’s been back here several times, but the last time he was here was in 1938. He went back for good then, and went out to South America to boost German trade there, but actually to do Gestapo work that would estrange the South American countries from the United States. He made out all right on that job, particularly in Argentina and Chile.”

The senior officer paused again, shrugged, and then continued with his story.

“Since then he has been like a lighted fuse ready to touch off anything that would hurt England’s cause, and ours. Cargos arriving from U.S. ports have mysteriously burned up on South American docks. And our ship owners have had to take the loss. Many England-bound ships leaving South America never arrived. In fact, they were never heard of again. And lately, many of our own ships have gone down, and crew members drowned, because of him. I even have a report that he was at Pearl Harbor on that back-stabbing day of December Seventh. We feel sure that certain mysterious munition plant explosions in the U.S. were planned and carried out by his sub-agents. He—”

Colonel Welsh stopped short, gestured slightly, and dragged down both corners of his mouth.

“I realize that all this may sound just a little on the fantastic side,” he said. “How could we possibly tell that he had a hand in all these things? Well, simply the way police forces can tell that a certain known criminal had a hand in several robberies, or murders, or what have you. The man’s mark. His trademark, you can call it. A definite little touch to each crime that tags it as having been committed by the same man. Well, we’ve run into that same thing with this unknown, Seven-Eleven, as we call him. A couple of things here and there that are identical with things discovered at other mysterious explosions, and so forth.

“In other words, there is one man behind most of the Nazi spy doings in the U.S., and Central and South America. He is the cleverest agent ever to come from Berlin, and the luckiest. But he is also the most deadly. Get in his way, and you’re a dead man. I’m sure he’d slay his own mother if it would help him any. But this I do know! Twelve of my crack agents, stretching from the Canadian border to the bottom tip of the Argentine, have been after him for months trying to trip him up, and catch him.”

Colonel Welsh cut off his words with a harsh sound, and there was the glitter of highly polished steel in his eyes.

“That man, Rigby, who just went out,” he said between clenched teeth, “is the only one of the twelve alive today. Eleven trained Intelligence agents dead, and we are no nearer to getting our hands on this Seven-Eleven than we were weeks and weeks ago. It’s enough to make me want to cut my own throat!”

The senior officer gave a savage nod of his head for emphasis, then rested his elbows on the edge of the desk, cupped his chin with his hands, and stared flint-eyed off into space.

Dave waited a few moments for him to speak again, but when the man remained silent he leaned forward a bit in his chair.

“You sent for Farmer and me, sir,” he said gently. “Did the job you had in mind for us have any connection with—with this Seven-Eleven?”

The Colonel looked at him, and grunted.

“Yes, it did,” he said. “The pilot you saw die was named Tracey. He was in charge of all our agents stationed in Central America, though he was working on the Seven-Eleven business alone. Officially he was assigned to the Ninety-Sixth Attack Squadron in the Canal Zone, but his unofficial job was to pick up any leads on this Seven-Eleven if he could, and follow them through.”

“And did he, sir?” Freddy Farmer asked eagerly.

“Yes, and no,” Colonel Welsh replied. “I mean by that that he ran across something pretty hot, I think. At least he sent word to me in code to arrange for his recall to the States for a short time. What he wanted, according to his code request, was leave of absence from his Squadron to follow up something. That was three weeks ago. Last night he sent word to me in Washington that he had flown out of Mexico into Texas, and up to Albuquerque. He asked me to meet him here, and to have two qualified Intelligence men present who were also pilots. I was unable to contact him direct, so I couldn’t learn more. I sent word to Rigby to expect him, and to expect you two, and myself. And of course, I sent you word to report at the Frisco Air Base. And—well, as to what happened after that, you know as much about it as I do.”

“Something big in our hands, almost,” breathed Freddy Farmer softly. “What rotten luck!”

“That’s putting it mildly!” Colonel Welsh growled. “God knows what Tracey’s death may have cost us—cost the whole world!”

“Maybe,” Dave murmured softly. “Maybe. But I made a kind of promise to Tracey. More of a hope, it was. A hope that Freddy and I might have the chance to carry on where he left off.”