Fred la Mothe was giving a party; not a large party, but one which Fred promised himself should be memorable. It was a dual celebration.

“I’m pulling a party at the Tuller to-night,” he told Potter Waite over the telephone. “Double-barreled. To celebrate my birthday and my election as secretary of dad’s concern. Dad admits I’ve come of age; says nobody comes of age until he’s twenty-eight, no matter what the statute in that case made and provided believes. He’s giving me a wad of stock and making me go to work. I guess I’m going to. So this is a farewell performance. Just a dozen of the fellows. You’ll be there?”

“What’s the use?” Potter said. “I’m cold sober these days.”

“Come and watch the rest of us.... Sort us out when it’s time to go home and see that we don’t bust in on the wrong families. There’ll be a taxi for every man.... And I’m planning to shoot off a cabaret stunt that will make Broadway look like a country lane.”

“Nothing doing, Fred.”

“Now look here, you and I have played together since we were kids. This is my big night and it won’t be worth a damn if you aren’t there. Forget your infernal motors for a couple of hours and be a regular fellow again.... I’m asking it as a favor.”

“Well,” said Potter, after a pause, “I’ll drop in for a while to watch the menagerie, but don’t count on my yowling with the rest of the animals.”

“You can be a keeper with a steel prod.”

“O’Mera be there? I hear he’s going to fly.”

“Goes to the ground school next week.... We’ll miss Kraemer and Randall. Kraemer’s here with a brand-new uniform and a commission, but lips that touch liquor can’t touch his’n while he wears it.”

“All right. I’ll show up.”

Potter hung up the receiver and arose from his desk to walk out into the shop. His office was not where it had been, in the administration wing, but occupied a corner of the shop itself. He had kept his promise to the men, and worked side by side with them, surrounded by shafting and belts, by lathes and planers and shapers, and the scraping, clanking, grinding roar of machines that turned out daily more and more work for the government. He glanced about him and was proud. Everywhere were units of motors, parts in all degrees of completion. At last production had commenced on such a scale as he had dreamed of, and now only weeks must elapse before he was turning over to the government a steady flow of motors that would continue day in and day out so long as the war demanded them. It was accomplishment.

From the day he had spoken to the men from the platform of a gray-painted army truck the work had seemed to leap ahead. The men had put in as their share something more than mere wage-earning labor. They had added to it enthusiasm. The spirit with which they worked day after day was splendid, and Potter made it no small part of his duty to see that it did not die out.

There were still annoyances, delays, petty mishaps. The campaign of sabotage had not ceased, but it had been checked, for Potter had now to depend upon an army of watchful, eager eyes, the eyes of every honest working-man, and not the few guardians set by the Signal Corps.... But Potter was not satisfied nor at rest. His foreboding grew as his efforts to lay hands upon the source of the trouble proved futile. He believed something was in preparation, that some blasting catastrophe was being planned and made ready ... which he seemed helpless to avert.

Like all his other days, this one passed too quickly. There were many times when he would have wished to be a Joshua. The machinery went to rest, the army of men filed out noisily, and Potter closed his door for the night. He drove home through the coolly pleasant December air and dressed. At seven o’clock he entered the lobby of the Tuller, where La Mothe stepped forward to greet him.

“The gang’s here,” he said. “Let’s make for the scene of the slaughter.”

There were twelve of them, young men all, not one of whom but carried a name which stood for wealth achieved or personal success. But it was a dozen which could be duplicated more than once in highflying Detroit. They moved in holiday spirit to the private dining-room to which La Mothe directed them, and found their places around a long, flower-laden table. The flowers heaped upon that linen had taken from La Mothe’s pocketbook a sum which would have kept a large family in comfort for a month.

A skilfully set table is a beautiful sight. There is something about the combination of white linen, flowers, silver, and glass which touches a chord in the masculine heart.... Perhaps this bears out the boyish belief that the Chinese place the seat of the emotions in the stomach. Potter’s eye took note of the number and variety of the glasses. Michigan would be afflicted by drought in May, but the drought had not arrived; here was promised a deluge.

The party seated themselves, and as each man lifted his napkin he found under it a cigarette-case of gold, engraved with his monogram.... Such cases, Potter knew, could not be had for a ten-dollar bill; indeed, he doubted if ten such bills would be sufficient. This night La Mothe was not flying near the ground. Financial worries did not seem to hover in his neighborhood. Those cigarette-cases, Potter said to himself, would have maintained a soldier in the field for twelve months.

With the cocktail started the entertainment of which Fred had boasted. A miniature stage with curtain and scenery had been erected at one end of the room, and upon it a performance went forward throughout the dinner. It was there. One might watch it if he chose, or might disregard it for conversation with his neighbor. It was an incident, but not an inexpensive incident. Fred’s idea of a proper cabaret seemed to consist in such sights as the safety of the performers would not permit in a cold room. There was nothing gross. Fred was possessed of too much of the esthetic for that; all was artistically done, skilfully done by performers of no mean grade.... The more perfect the art the less necessary the apparel—that seemed to be the basic rule.

Eldredge sat next Potter; across from him and lower down the table sat O’Mera and Cantor, side by side. Potter had not expected to see Cantor there.... Potter glanced about. There was not a young man present who could not have afforded to give this entertainment or who was amazed at the luxury of it.... He did not glance at Cantor. The sight of the man was hateful to him; the surge of hatred which welled up from his heart held him tense, forgetful of his surroundings, and he sat staring moodily at the table before him. La Mothe perceived his mood and called, jovially:

“Come out of it, Potter. The mourners aren’t due yet. Wait till we have a little poker.”

Potter smiled back, forced himself to cast off the mood, compelled his mind away from Cantor. It was a thing not easy to accomplish. Every time he headed his thoughts away from the man they dodged around and approached from a new angle. He set his teeth and plunged into conversation with Eldredge. It was not an intelligent conversation, and more than once, when Potter gave vague replies or forgot to reply at all, Jack wondered what had gotten into his friend.... He was thinking now of Hildegarde von Essen—thinking bitter, unsavory thoughts. He refused even the lightest of wines, not because he was afraid of the exaltation, but because he knew himself, knew his rash impulsiveness, knew the difficulty he had, sober, to hold himself in hand. Inflamed by stimulant, he could not answer for his conduct, and it would be an ill thing to interrupt La Mothe’s party by flying at Cantor’s throat.

The others were not so cautious. Glasses were filled and emptied. Waiters seemed to fear some calamity if a man were left with an empty glass before him. The party, like all masculine affairs, had been sedate, a trifle strained at the beginning. It was easier now. It was no drunken revel, no orgy, but tongues were set free, wits were kindled, the whole tone was lifted a key, and the signature was never in flats—always sharps.

The time had been when such a party would have revolved around Potter Waite, when he would have given it its tempo—and the others would have found it not easy to follow his time. His presence was always desired, yet it was welcomed with a certain apprehension, for limits known to others did not bound him. Even now the young men in his immediate neighborhood felt a premonition that something reckless would happen. They were doomed to disappointment. The gaiety went on without him, in spite of him. He was not enjoying himself; indeed, he felt out of place and was rather piqued with himself that he should feel out of place. The truth was that in one year he had grown beyond such things; had graduated from that school, and its curriculum had nothing to offer him. Frankly, he was bored when he tried to enter into the spirit of the evening.

But his efforts were not long continued. He sat gravely listening, or covertly watching Cantor and thinking of Hildegarde. It seemed impossible, monstrous, that he should sit peaceable at the same table with that man and restrain his fingers from the man’s throat.

Suddenly he leaned forward and listened. He could not have told why, but the word “aeroplane” had touched his ear. It was a charm to command his attention; it had called to his subconscious self.

“Yes,” O’Mera was saying, “I’m going to have a try at it next week.”

“You’ve picked the only branch worth a man’s while,” Cantor said, and Potter was conscious of wonder at the enthusiasm that flamed an instant in the man’s voice. He had known Cantor well. Cantor had been about his hangar, yet the man had never shown an especial interest in aviation.

“They’ve loaded me up with the notion that I’ve got to work,” O’Mera said. “Maybe so, but I don’t see why it shouldn’t be about as easy to drive a ’plane as it is a car.”

Potter glanced sidewise at Cantor, saw his eyes were extraordinarily bright, his usually colorless cheeks were tinged with red. The wine was exhilarating him, stirring his blood to quickened movement and unleashing his tongue. Usually there was an air of reserve, the appearance of weighing each utterance, about him. It was not evident now. Potter set himself to listen.

“You’ll find enough to learn,” Cantor said, and plunged into an explanation of what must be learned and how it must be gone about—an explanation that was thorough, interesting, full of expert information. Potter was astonished. He was something more than astonished, he was filled with a thrilling excitement, the excitement that comes to a man when he feels he is standing at the gate of some climax.

Cantor was explaining such erudite matters as the tail-spin, the nose-dive, looping the loop, and how one gave his machine the spurious appearance of fluttering downward out of control—so to deceive an unwary adversary. He was very clear, very positive. No man, thought Potter, could talk like that who was not a master of the air, who had not been a super-skilled pilot.... What did it mean? Where had Cantor flown? Why had he concealed this ability?

“They tell me,” O’Mera said, “that we’ll get the final touches in France or Italy or Egypt. I hope I go to France. Somehow flying in northern Italy, with Alps sticking up under one, doesn’t sound attractive.”

“It’s not bad,” said Cantor, confidentially, “not really bad. Just fly high enough. What’s the difference what’s under you?”

“You talk as if you flew over the Alps every morning before breakfast,” said O’Mera, with a laugh. “I didn’t know you had even been off the ground.”

“Did I say I had been, eh?” Cantor said, a trifle tipsily. “Did I say I was a flyer? Tell me that? No, I just told you how to fly. Very different thing. Everybody knows how to fly. Books are full of it. I could read it out of books, couldn’t I?”

“I suppose you could,” said O’Mera, a bit belligerently, “but you didn’t say that you did. What you said sounded as if you knew—like it was first hand.”

“Maybe it was, and maybe it wasn’t. What’s the difference, anyhow?” He drained his glass and looked about for the waiter. “You wanted to be told, and I told you. And I told you right.... Who said I was ever up in the air?”

O’Mera shrugged his shoulders. His Irish head was hard, and liquor had a way of battering against it futilely.

“And who said I wasn’t?” Cantor wanted to know.

“Search me,” said O’Mera.

“Well, let me tell you something, O’Mera, something about the Alps.... They can be flown over—because they have been flown over. Yes, sir, right from one side to the other.... And who was the first man that did it? Tell me that.”

“I haven’t the least idea. Ask yourself the answer.”

“What difference does it make—so long as somebody was the first to do it? Somebody had to be first, before there could be a second. First comes first—second comes second.” He emptied another glass and set a cigarette unsteadily in his lips. All the while he peered at O’Mera with supercilious and sardonic humor. “That’s fact—isn’t it?”

“Sounds logical.”

“Over the top—from the plains on one side to the plains on the other.... Who was the first man that did it? You’d like to know.” He lowered his voice confidentially and said in a stage whisper, “You’ll have to ask somebody else.”

Potter knew who was the first man to fly over the Alps. There was little about the history and development of the aeroplane that he did not know. He remembered how the newspapers had heralded that feat and the name of the man who had accomplished it. The man had been a German, an officer; he had been decorated for it by the Kaiser himself. The name of the aviator was Lieutenant Adolf von Arnheim.

Potter was excited. Was it a discovery? His suspicions of Cantor were reawakened, made vivid. He fancied he now had real basis for suspicion, for if his intelligence were not at fault the man had intimated in his tipsy way that he had topped the Alps in an aeroplane, had even seemed to verge upon the boast that it was he who had first accomplished that feat. Potter reviewed the conversation, weighed and valued each word. Did his desire to believe the thing make it appear to be true?... He thought not. He believed he had put a warranted conclusion upon what he had heard, and that Cantor in his bibulous state had been upon the verge of making a revelation.... From that point reasoning walked in a straight path. Either Cantor was lying boastfully or he was the first man to surmount the Alps. If he were the first, then his name was not Cantor, but Adolf von Arnheim, and he was an officer in the Imperial German army!

Potter argued with himself, presented the evidence to himself again and again, and scrutinized with what fairness and calmness was possible. Clearly Cantor had an unusual knowledge of aeronautics, the knowledge which only experience could have given—experience of the most profound and particular study. Cantor did not seem a man likely to gain such knowledge from poring over a text-book.... If, then, Potter accepted the conclusion that Cantor was an aviator, the other conclusion was not so grotesquely remote. It crystallized his suspicion into certainty—a certainty that Cantor deserved scrutiny.

Either the man was a boastful, tipsy liar or he was Lieutenant Adolf von Arnheim, whose tight lips had been betrayed by the fumes of wine.... If he were von Arnheim, then he was a German, an officer—and a spy!

Here were such suspicions as must be put to the test, such conclusions as did not admit of delay in their verification.

The matter spread out before Potter with sinister ramifications. Fact fitted into fact. One of the facts was young Matthews’s vanished aeroplane. Granting that Cantor was a spy and one of Germany’s most skilful men of the air, then the aeroplane would be in his thoughts as a means to bring about his campaign of destruction. In the hands of such a man an aeroplane would be frightfully effective.... Potter’s mind leaped past the basis for his deductions. If Cantor were von Arnheim, then Cantor had stolen Matthews’s aeroplane, and Cantor intended to use it to Germany’s advantage. Germany had sent him there for the purpose.

But suspicion, individual certainty, were futile. Potter had to know. He must identify Cantor as von Arnheim past all dispute, and he must do so quickly, without arousing Cantor’s suspicion.... Cantor unsuspicious was a menace; Cantor with suspicions aroused would be swift-striking lightning. He might not be ready to launch his catastrophe, but let him suspect that he was watched or under investigation and he would act swiftly, terribly.

The last course had been served, the entertainment on the miniature stage was reaching a climax of unclothed vivacity, the room was as full of smoke as the heads of La Mothe’s guests were with the lilting voices of the wine. Excitement had been aroused and demanded to be satisfied. To those young men excitement wore two faces, girls and gambling, and gambling drew the vote.

“Who said poker?” Eldredge called.

“Clear out these tables.... Bring cards and chips and card tables,” La Mothe directed.

“Two tables, six to a table,” Fred said.

Potter made his way to his host. “I’m off, Fred,” he said. “I’m a laboring-man. It’s close to midnight.... Somehow I don’t fit in as well as I used to.”

“Oh, stick to the finish. I’ll guarantee there’ll be a finish.”

“I’ve lost my taste for them,” Potter said. “I’m sober, and you fellows have a sheet to the wind. No.... I’m off.”

La Mothe shrugged his shoulders. “Sorry,” he said. “Good night.”

Potter went out quietly, leaving behind a party that would not break up until daylight, a party who would play for the joy of play, with the blue sky as their limit.... The dinner with entertainment and favors had cost La Mothe in the neighborhood of three thousand dollars. As matters turned out, it was not such a bad venture in highflying, for when he cashed his chips at five o’clock in the morning he found he had paid for his celebration and had eight hundred dollars surplus to set down on the right side of the ledger.