Bob Gordon was reading a letter from his mother as he sat in the principal room of a little farmhouse outside of Cantigny. The place had long been abandoned by its owners, and now sheltered a dozen American airmen and as many mechanics, in spite of the serious damage it had suffered when the town was taken. Bob was seated on a three-legged stool, tilted dangerously as he propped his feet against the chimneypiece—or what was left of it in a heap of brick and mortar fragments. The morning sun streamed in on the earthen floor and fell across his face as he read the closely written lines. His thin, brown cheeks were tinged with healthy color, and his whole lean figure in its well-worn khaki looked full of life and vigor. But just now his face was serious and sad, and the eyes he raised from the letter toward the sunny window were darkened with painful anxiety.

He could see his mother’s pale face before him as he read, her lips set with that brave firmness that war-time women learned to keep in the midst of fear and suffering. Even in her letter she tried to hide her thoughts, and to write hopefully for Bob’s sake, though she spoke frankly of the trouble they shared together.

“I can think of nothing but Lucy, Bob, wondering when the time will ever come that I shall see her safe and beyond the power of the enemy. But since that night you saw her with Elizabeth, I can find courage to hope again. How strange things are—the dreadful and the good all mixed together! For I feel so sure that your father would not have made his wonderful recovery if dear little Lucy had not been there beside him.”

Bob looked up once more, pondering. His reveries these days were one long rebellion against his helplessness. All his courage and strength of purpose were not enough to bring his little sister out of ChÂteau-Plessis across the hotly contested battle line. He and his comrades had all they could do to hold back the German tide, without yet advancing to retake the town. The success of the American troops at Cantigny could be repeated at ChÂteau-Plessis—must be—but not without adequate plans of attack and further reinforcements—those reinforcements that every one wanted at once. “Thank heaven, our men are coming overseas now at a good rate,” he thought with a sudden hope illuminating his dejection. “And things seem just endurable in ChÂteau-Plessis. The Boches are few enough there, except those who are flat on their backs.” For Bob had news from inside the captured town of which Lucy never guessed.

His restless and unsatisfactory thoughts were cut short by the sound of a footstep on the stone threshold behind him. He swung around toward the door, while the newcomer at sight of him exclaimed:

“Here you are, Bob! I’ve been looking for you on the field. We’re to go up at once. The sergeant is running around with orders just telephoned from up the line.” The speaker was a young aviator about Bob’s age, so wrapped up in his leather helmet that little of his face could be seen but a pair of twinkling blue eyes.

“What are the orders, Larry?” asked Bob, getting up and cramming his letter into his pocket. “The guns don’t seem to be firing very heavily.”

“No, it’s the same old business. The French observers are trying to get a peep at Argenton. The Boche scouts seemed to be asleep for a while and the French made some bold swoops, but now the enemy has waked up with a vengeance, and if the observers are to see anything they must have some guards to engage the Boche. Where are your duds? I’ve got to go back to my plane. You’re to go up with Jourdin, I think. He’s got two fine new machine guns on his Spad—you ought to bring down half the German air force with them. Well, I’m going.”

Bob slipped into his flying coat, put on his helmet, picked up half a dozen things he needed, and went out just as the sergeant met him at the door with the orders in his hand.

“All right, Sergeant; I’m off,” he said, returning the salute. “Where is Major Kitteredge, do you know?”

“He’s on the field, sir, or was a minute ago. I think the Lieutenant will find him near the stables.”

The sergeant pointed across the farmyard to a broad field behind it, and Bob nodded to him as he started off. The sergeant was a friend of his, and Bob never had a moment’s talk with him before his thoughts turned with a pang at his heart to that other friend, Sergeant Cameron, whom he had left behind in a German prison. He had sent him many packages of food and comforts since then, and had even received a printed card of acknowledgment from him, forwarded under Red Cross supervision. But what were presents of food and tobacco—priceless as they were to the prisoner—compared with freedom and a chance to strike a blow in the good cause on such a day as this?

Bob crossed the farmyard and vaulted the fence into the hay-field. The old barn had been converted into a workshop, and near it stood a dozen men preparing for flight. Six biplanes were waiting on the field, to some of which the mechanics were giving a last careful inspection. Bob found Major Kitteredge beside one of them.

“Good-morning, Major,” he said, saluting. “Any further orders for me?”

“You are to go up as gunner to-day, Gordon,” said the officer, looking up from the papers he held. “We’re short one gunner, and Jourdin wants you. He has received all the orders I have here, so he will pass them on to you. Get off as soon as possible.”

“Yes, sir.”

Major Kitteredge had known Bob when Bob was twelve years old and he, the Major, was a lieutenant in his father’s company. In their most formal intercourse there was an undercurrent of friendliness never quite hidden. He watched Bob keenly for a second now, as the young officer crossed the field to Captain Jourdin’s side.

“You are here, eh, Gordon?” said the Frenchman, throwing away his cigarette with a smile of welcome. “Then we will lead the rest and be the first off the field.” He drew on his gloves and shouted orders to his French mechanics, who shouted back “Oui, mon capitaine!” through the whirling of a propeller close by.

The big biplane in which Bob now took the front, or gunner’s seat, strapping himself in behind the two machine guns, was a far different craft from the little thirteen-metre monoplane in which he had landed behind ChÂteau-Plessis. Foreseeing, that night, that he might have to dodge and fly for his life, he had chosen one of these swift, strong little hornets, capable of performing the most breakneck evolutions at incredible speed. But this morning he and Jourdin were out to face and force back the enemy, and the heavy-armed Spad was built for combat.

Jourdin gave him the plan of operation in a few quick sentences. The biplanes were to act each one independently, attempting to drive off as many as possible of the enemy planes from their own scouts. At the same time they must keep a sharp lookout for whatever information they might be in a position to pick up.

“We will fly north to ChÂteau-Plessis, then on to Argenton,” he finished. “Try the speaking-tube, Gordon. All right? Eh, bien! Partons!” he shouted to his mechanic, who responded by giving a twirl to the propeller which sent it spinning.

Jourdin opened his throttle and pressed forward on the control stick. They were off down the field in a buoyant, bounding rush. Bob settled himself comfortably, fastening the flap of his helmet. Jourdin pulled back his stick, and the machine steadied to a glide, swaying ever so little. The rushing grass disappeared from alongside and in a moment the earth had grown a distant scene below.

In ten minutes they were flying swiftly northward at a height of four thousand feet. Two other flyers had risen from the field after them and were in close pursuit. No enemy planes as yet disturbed the solitude, and Bob fell to looking over his machine guns, the cold air of these high spaces blowing pleasantly against his face. Jourdin led the way confidently for the little squadron, and where he led any airman was well content to follow. In half an hour they were over ChÂteau-Plessis, while below them the German trenches spouted fire from long-range anti-aircraft guns. The bombardment at this point was not heavy, the enemy’s persistent attempt to push the French and American line further west having met with dismal failure. A few German airplanes darted up from their guard over the trenches, but Jourdin had no desire to engage in battle here. He pointed his machine upward, and Bob had no more than a glimpse of the little town that meant so much to him, before they had mounted to five thousand feet, just below the clouds which hung under the deep blue arch in soft fluffy piles. Below them the enemy planes had given up the chase. The town was only a little square made up of dots and lines. Before it, where the trenches ran, rose little smoky puffs that hung in the still air. Even the bursting of the shells was deadened to a dull roar. Captain Jourdin spoke through the tube.

“We’ll go a little higher, Gordon, and hide behind those clouds. We shall sight the enemy any moment now, and shall have the advantage if we take him unawares.”

While he spoke ChÂteau-Plessis was left behind. Argenton was only fifteen minutes distant. Again he pointed the big plane upward another thousand feet, into the midst of a great enveloping, smothering bank of cloudy vapor. The soft, cottony mass gave way, dissolving into clinging wisps of fog that trailed along with them like streamers. Then they burst through a hole in the cloud roof into the upper sunlight—a world of celestial loveliness. Often as Bob had risen above the clouds, he could never do it without marveling anew at the strange beauty around him when the airplane pushed its way through the last foggy barriers. No sky, however beautiful, seen from the earth could compare with the absolute clearness of the dazzling blue about them. Below, the clouds were banked again into close, white masses, tinged here and there with a gold edge where the sun struck them. A mile behind came following two growing dots—a part of the squadron which, it seemed to Bob, had laid aside for the moment all thought of battle and, like themselves, were idly exploring this upper dreamland.

A rift in the clouds below put an end to these thoughts, for through it he saw eight airplanes darting back and forth, maneuvering for position. Beyond and below them, near the narrow line of the Avre River, lay the town of Argenton, and, another mile to the west, the old medieval fort behind the fortified ridge. Bob turned his binoculars upon the moving planes, and as he focused the glass he spoke to Jourdin. “Do you see them? Go down a thousand feet.”

“All right,” returned the pilot promptly. He pushed the stick and the machine dropped swiftly. Bob could see the Allied emblems now on the tails of three of the planes. They were French scouts, and the other five were German Taubes, distinguished by their shape as well as by the great black crosses painted on their wings. At a little distance another group was swaying in combat. He shifted his glass to these and saw that here Allies and enemies were equally matched. Two French scouts and one American battle-plane were fighting three German fliers.

Jourdin seemed to divine his thoughts, for, without waiting for a signal, he bore swiftly down upon the Taubes which had surrounded the three Frenchmen just below and were pouring a deadly fire upon them. The scouts were willing enough to run away but, unable to do so, were fighting gamely against impossible odds. Another moment and Jourdin had brought his plane and its weapons into range. Bob turned the trigger handle of his machine gun and pumped a hail of bullets into the wing of the Taube nearest him. He saw the German aviator dart a glance upward as he tried to get his plane out of range in a quick climbing turn. But, before he could sheer off, his wing hung warped and crippled, the silk out almost to ribbons. The pilot pointed downward, making a try for a landing on one wing, three thousand feet below. Bob saw no more of him. He turned his gun on a Taube which had abandoned the scouts and was firing at him with furious and accurate aim. The bullets whizzed about the big battle-plane, but Jourdin did not remain an easy target. He took a tail-spin, dropped in short circles for a thousand feet, then came up again behind the enemy. Two more Americans had now arrived to engage the Taubes, and the scouts were out of danger. Jourdin spoke into the tube at Bob’s ear. “We’ll go on west. We’re not needed here. I should like to follow our scouts, who are making for the defenses.”

As he spoke they mounted a little and flew off toward the edge of the town marked by the German trenches. A second plane of the squadron followed them as they crossed the French lines and flew over the enemy’s trenches, above the fortified ridge. Below, the anti-aircraft gunners were sending up a continuous fire of shells to hinder their further descent. Around them hovered the French scouts, vainly endeavoring to catch a glimpse of the camouflaged defenses through the curtain of fire and smoke spread out beneath them.

“It isn’t a bit of use,” Bob thought bitterly, after half an hour of this useless watching. “What can we see from here? We are keeping the Boches from sending more planes after our scouts, but What does that amount to?”

As he fumed in helpless impatience, scheming a desperate attempt to penetrate that curtain of fire, Jourdin’s calm voice, in its deliberate-sounding English, came to him with a shock of reality.

“We’ll go down now, Gordon. I have orders to report at noon through the field telephone station near here, behind our lines. Our squadron can be called together, and at least put some of these Taubes out of the combat. The scouts can accomplish nothing now.”

“All right,” Bob answered reluctantly. He was roused to the point where it was hard to give up without having done anything more than scare off a few German fliers. “Well, the day’s not over,” he consoled himself, casting a resentful glance down at the German defenses along the ridge, where smoke and flame were spouting from a dozen batteries. The pilot’s feet were on the rudder and already the plane was making westward again across the French lines.

Though Captain Jourdin was flying only temporarily with the Americans at Cantigny, he had been given orders to report the morning’s events to headquarters, because he could do so with the greatest ease and dispatch. To most of the American fliers the country along the battle line was still a thing to be puzzled out with the aid of maps and glasses by day, and stars and compass by night. But to Jourdin it was old and familiar ground, for this part of Picardy was his home, and these ruined fields and villages he had known since boyhood. Bob thought of Argenton only as a town half destroyed by shell-fire, a place he could always find easily from above, because of the still-standing towers of the old fort behind the blazing line of German batteries. But to the Frenchman it had a different meaning. It was the little town whose quaint, cobbled streets he had often passed through on summer days in his childhood to visit his grandfather, whose old home outside Argenton was now a ruin. If it was late enough in the afternoon the peaceful townsfolk had brought their babies out to the old fort to hear the sunset bugle and see the soldiers change guard. No one would have believed in those days that the Germans would ever hammer at its gates and take possession.

Behind the French lines the country stretched in rolling fields to a burned wood. Jourdin steered for a little clump of larches beside which was a telephone shack, sheltered by a bit of rising ground. Bob had the glasses at his eyes, and swiftly picked out a landing-place.

“To the right, Jourdin—make it a hundred yards before you dip. There’s a nice level bit before those shell-holes begin.”

The pilot leisurely studied the ground, shut off his gas, and glided beautifully downward until the earth rose to meet them with a rush, and the wheels of the big plane touched and ran along the grass to a gradual standstill.

Bob unstrapped himself and got out, glad to stretch his legs. But the next moment he caught sight of a wire slightly out of adjustment on the plane’s broad wing, and pointed it out to his companion. “That can’t be left, Jourdin. Shall I fix it while you go to report?”

“There’s a mechanic in the shack. I’ll bring him out,” said Jourdin. “If we wait for the repair, let us take this chance to eat our ration on the ground. We shall have fifteen minutes.”

“Good idea,” said Bob with enthusiasm. As Jourdin walked off toward the shack he brought out the little packages of food and laid them on a convenient rock. For a moment he forgot his disappointment at the morning’s failure. Nothing can rouse such an appetite as flying, and Bob had not yet learned to enjoy a meal snatched on the wing. He could read, write, think, in fact do many things during a swift flight, but he liked to eat on level ground.

When Jourdin returned and set the mechanic to work, the two young aviators took off their gloves and helmets and, sitting down, devoured their rations of sandwiches and chocolate, along with a canteen of cool water.

A gentle breeze was blowing from the west across the blackened fields. It blew the drifting smoke away from them, and except for the noise of the shells, it seemed almost peaceful in the deserted meadow. Above them the airplanes still floated, but none very near. For the time being the French scouts had given up their search. On a little rising ground not far off stood a ruined windmill, its burned stumps of arms stretching out dismally above level shell-plowed earth that had once been a green wheat-field. There was an old brick chimney near it, too—all that was left of a little farmhouse. “The Allies have got that much back, anyway,” Bob thought. “The Boches were here last winter.”

Captain Jourdin had risen to his feet and was looking off across the fields in silence. More than once in their familiar intercourse Bob had recognized moments when the Frenchman’s devoted heart was bitterly wrung, and his whole mind distracted from his work at sight of some such hard reminder of his country’s fate. The hands clasped behind his back clenched themselves tightly together as, turning, he said to Bob, “I remember the windmill when that farm was a prosperous little place. The farmer had lived there many years.”

Bob could not think of any answer. There was no asking for pity or encouragement in Jourdin’s calm, melancholy voice. It held more of resolute defiance than any German’s burst of bravado. Bob thought of the lines he had read in an English paper a few days before. They were Spoken by a Frenchman, looking over the ruined fields of France, almost as though the writer had seen Jourdin’s shining, dark eyes and written for him:

“C’est fini, mon capitaine,” said the soldier-mechanic, coming up with a quick salute and a backward gesture toward the airplane.

Bob picked up his helmet, while Jourdin followed the man over to inspect his work. Bob looked up into the blue sky, streaked with feathery cloud streamers, devoutly hoping for better success in the afternoon’s offensive. A desperate eagerness took hold of him once more. He had learned a part of the secret of the French soldier’s valor—what it means to be fighting to rescue one’s family and home—since his father and Lucy were prisoners in ChÂteau-Plessis.

“It is all right now,” said Jourdin, turning, as Bob came up, from a critical examination of the wing’s supports. “Let us get off at once. Look there!” He pointed upward to where three German planes were deliberately crossing the French lines, from which several aircraft quickly rose to intercept them.

“Most of our little squadron stayed near ChÂteau-Plessis to engage the enemy there,” said Captain Jourdin. “I think we shall be needed to help drive these fellows back.”

As he spoke so modestly of what might be expected of him, the light of battle shone in the Frenchman’s eyes. He hurriedly completed his preparations for flight. Bob, no less eager, seconded him in silence, with one more quick glance at the planes now circling overhead. In five minutes they were off down the meadow, and rising swiftly toward the scene of the fight.

No sooner had the Germans seen the French planes mounting to the attack than they sent reinforcements from their own lines. Evidently the persistent hovering of the Allies’ scouts over the Argenton defenses was beginning to annoy them. According to their usual tactics when suffering from wounded dignity, they prepared to take the offensive. As the battle-plane carrying Bob and Jourdin approached a height of six thousand feet, and came on a level with the combatants, the situation had not as yet advanced beyond a skirmish. There were eight enemy and seven Allied planes, not counting the newcomer, which evened the numbers. Of the French and American planes, three were heavy machines from the Cantigny squadron, the remaining five light, scouting craft. The Germans were all armored planes, but three were of a heavy, slow-going type, almost invincible by bullet fire, but unable to quickly follow up an advantage. Jourdin gave one keen look around him, as though summing up the odds, then spoke through the tube to Bob:

“We have a good chance of victory, Gordon, but we’ll have to fight hard for it!”

Bob was already convinced of that. He caught sight of Larry Eaton on his left, pouring a murderous fire from his Lewis gun into the heavy German craft maneuvering beside him. But he also saw the man who skilfully guided the Boche machine into position for a swift retaliation on Larry’s flank. This pilot was Von Arnheim, the German for whom Bob had been exchanged. One of his feet had been rendered useless by shrapnel fragments, but that had not prevented his returning to the air service. His steel-blue eyes shone out from behind his helmet with all his old reckless audacity, and Bob felt his determination harden and his courage mount to fearlessness at sight of him.

A big German plane swooped down upon him as these thoughts took shape. He saw the gunner jerking his weapon into range. A bare second quicker than his enemy, Bob began pumping his port machine gun. A jet of flame burst out, and the next moment the German machine quivered, its planes twisted to one side, and like a shot bird it fell from sight.

Through the tube Bob faintly heard Jourdin shout, “To the left—look out! I’ll put you in range!” He had no time to take breath after his recent victory, before two more of the enemy were upon him. The privilege of flying with the famous French ace had its perils, too. Every Boche who could manage to do so made for Jourdin, hoping to down the hero who, once already disposed of, had returned by some miracle to active service. Jourdin brought his machine around in a climbing turn to avoid one aggressor, while Bob pressed the handle of his starboard gun, hoping to rid himself of his right-hand opponent. Instead of the burst of flame which should have resulted, the gun remained silent—jammed.

Bob frantically maneuvered his other gun into position, but the Boche had opened a deadly fire upon him. Bullets spattered through the wings and whizzed around him. At the same instant a third enemy descended from above. Suddenly a machine gun began firing from the other side. Bob saw Larry Eaton’s face behind it, and the next moment his newest antagonist wavered, tilted, and the wreck hurtled down six thousand feet to earth. Bob could catch only a glimpse of this, for Jourdin had grasped the need of a momentary retreat. He made a tail-spin, fell a thousand feet, then, having thrown off his enemy, rose in a climbing circle while Bob remedied the jam in his gun and looked around for further developments.

He had not long to wait. Close beside him a German plane was getting into range, and now it began a heavy fire in the midst of a series of plunging dives which did not allow Bob to return the fire with any effect. Jourdin made another tail-spin, hoping to come up beneath the enemy, but the German was too quick for him. He dived again and came up in a swift turn beside the Frenchman, pouring out a hail of bullets. Bob was at a white heat of rage. “Once more, Jourdin!” he shouted.

The pilot dived again, simultaneously with the German, and this time the enemy was caught at his own game. Jourdin slowed up and let the other plane sweep past. As the Boche shot upward he followed close in his wake, and for the first time Bob poured shot after shot from a range of a few feet. The big German machine continued swiftly upward, then it lost speed, fell tail foremost, recovered, and finally nose-dived to the ground.

Bob drew a long hard breath and glanced below him. The Allies were holding their own, but two of them were missing. Of the German planes three were gone. He saw no more than this before another airman made for him in a climbing turn. The two planes were in easy range and each gunner began to pour a deadly fire on his opponent. The bullets spattered around Bob over the big plane and lost themselves in space, and still both machines remained uninjured. Jourdin maneuvered with all his skill for an advantage, but his antagonist matched him at every turn. Bob had not even to snatch a look at the enemy pilot to know whose hand was on the throttle. Von Arnheim, pale and shining-eyed, sat behind his gunner as though calmly awaiting victory. But it would not be quite so easy as that, Bob thought. His mind was wildly excited, so that the sudden burning pain in his left shoulder seemed to be only a part of his mad eagerness. Jourdin dipped and rose with incredible skill. The fire from the enemy was growing haphazard as the target dodged in every direction, and Bob’s steady hand on the trigger grew steadier as his brain grew hot and throbbing. Suddenly Jourdin gave a shout. The gunner of the enemy plane fell forward across his starboard gun. Von Arnheim snatched at the weapon beside him, but in that second Bob had sent a burst of fire through his right plane. The German gave one flashing glance at the torn, bullet-riddled wing, and pushed upon his stick. His big machine pointed swiftly downward. The next instant Jourdin followed, but this time Bob’s fire was less accurate in that dizzy descent. At three thousand feet Jourdin stopped in his downward flight and hovered, for Von Arnheim, useless wing and all, had guided his plane to a safe landing inside the German lines.

For a second Bob’s disappointment outweighed all his victories, as his eyes followed his enemy’s retreat. He had risked death to go down inside his own lines, and Bob understood that feeling. He thought Von Arnheim would have it in much stronger measure if he had ever endured the German sort of captivity. Bob knew that never again could he let himself be taken prisoner. From the French trenches over which they floated came a faint sound of voices. He peered over the side of the cockpit and saw hands and helmets waved in the air. They were cheering! His heart leaped with a sudden exultation. Then he glanced upward. The Allies were four to two—victory there, at any rate.

“Jourdin, do you hear them cheering?” he asked through the tube, and as he spoke a strange and painful weakness overpowered him until he clutched at the hot barrel of the gun at his right. Cautiously he felt of his aching shoulder and drew away a hand wet with blood. “So that’s it,” he murmured. “I’ll have to go back, Jourdin—I’m sorry,” he said, unsteadily.

The pilot’s quick eyes had already seen the red stain oozing through Bob’s torn leather sleeve. With a swift touch he sent the plane speeding through the air at ninety miles an hour, its nose pointed, above the silver ribbon of the Avre, back toward the safe shelter of Cantigny.