EVEN as the lads had started from the river’s edge inland to where their own lines stretched away to seemingly endless distances south and east, the moon which had been such a handicap to them in their sortie against the Germans hid its light behind gathering clouds, and that which had developed into a steady drizzle before they reached their company’s quarters was now a veritable downpour as they turned in for the night.

Truly, they were in France! As Ollie remarked between vigorous tugs at a mud-caked and water-soaked shoe that was reluctant to leave an aching foot, it was unbelievable that it could rain anywhere else with such persistency and in such quantity.

“I don’t know what country is on the opposite side of the earth from France,” he said, with a vehemence engendered by the weather, his shoes and the experiences he had endured, “but I’ll wager it’s a mighty fertile land whatever and wherever it is.”

“Hope it grows men who know how to keep quiet when others want to sleep,” a deep bass voice grumbled out of the darkness of a corner which the boys up to that moment had thought unoccupied.

“Buck Granger!” George Harper almost shouted. “Of all things unexpected! When did you get back?”

“Caught up with you again about noon,” Buck answered drowsily. “They thought they had me for keeps, I guess, but I’m limping along all right. I’m back to hand Fritz something as good as he gave me.”

The meeting took on the characteristics of a family reunion, for really the lads had not realized what a warm spot Buck occupied in their hearts until he had fallen, as they thought, mortally wounded, the day before. And so, despite his sleepy protests, they kept up a running fire of questions and conversation for the next ten minutes.

“Well,” said Buck at last, as though in retaliation, “now that you’ve about pumped me dry, suppose I turn the tables and ask what you fellows have been doing out so late as this?”

“Fair enough,” answered Tom laughingly. But before they were half through telling him of their experiences of that evening, and all they had been through since he had last seen them, Buck was sitting up wide awake and plying them with interested queries upon this and that phase of their harrowing escapes and thrilling captures and adventures.

“Say!” that energetic youth finally ejaculated. “I’d have given a whole lot to have been along.”

“Wish you had been,” said Ollie, with deep sincerity. “There were times when we certainly needed you.”

“It means certain and early promotion for all of you, of course,” Buck went on, “and promotion is certainly worth striving for; but it isn’t that so much as just having been through such things.”

The other three lads nodded in silent assent.

“Just imagine, Tom,” Buck Granger went on, with increasing enthusiasm, and turning toward the newly-made sergeant, “just imagine the yarn that will make for a little snoozer you’re joggin’ on your knee when you’re a grandfather, eh?”

“Say, look here,” Tom interjected, in a startled tone.

“Oh, that’s all right,” Buck went on. “You expect to be a grandfather some day, don’t you, if you get through this all right?”

“Your mind certainly can cover great distances in a short stretch of time,” Tom objected again.

“Yes, but that story will make any kid proud of his grandpap,” Buck continued, while George and Ollie chuckled at Tom’s evident discomfort. “Why, that would make any youngster wish he had been living in the days of the taming of the Boche, just to have knocked off a few of them himself. Yes-sirree!”

And when Ollie knew by the sound and regular breathing on either side of him that both Tom and George were sound asleep, and he himself was about dozing off, he heard Buck mutter, in a self-accusing tone, “By gosh, I’m an unlucky guy; nothing like that ever happens to me.”

Then Ollie slept. It could not have been long thereafter that Buck Granger also drifted off into the land of sleep, to have this rest interrupted with vivid dreams of personal participation in all the incidents that his three friends had so modestly related to him.

What wakened Buck he could not tell, but he knew it was hours later and that the rain was still falling and that it was yet dark, although probably beyond the hour when, had it been clear, dawn would have been breaking. But it was not the mystery of what had wakened him that bothered Buck so much as it was that terrible feeling that possessed him—that unexplainable, indefinable feeling that we all have at times, when for some unknown reason we feel certain that something is wrong and we know not what, or why we feel it so keenly.

The four youths were billeted in the small section that remained standing of what once had been a cow-shed. Yes, here once had been a fertile farm, the home and the support of a thrifty Frenchman and his family. And now it was a vast shambles and ruin, with only a part of the cow-shed remaining as tragic testimony to its earlier estate. Not very luxurious quarters, you may think! But real luxury, after all, when compared to water-logged trenches and rain-soaked, rat-ridden dug-outs.

As Buck first came out of his sound sleep he was conscious only of the ceaseless, pitiless hammering of the rain upon the rusted tin roof of the shed within which he lay—conscious only of that and of the indefinable feeling, which he could not overcome, that something was wrong.

And there is nothing that so unpleasantly grips the mind and the imagination, and causes the heart occasionally to miss a beat, as that tense waiting, waiting, waiting which accompanies a premonition of impending evil or danger—born of no one knows what—which comes to one with sudden awakening in pitch darkness and amid strange surroundings.

So it was that even as Buck Granger lay there, fully aware now of where he was, and listening to the even breathing of his three friends who were stretched out not more than ten feet away from him, something happened which seemed almost to make the blood freeze in his veins.

It was a moan! Weak, subdued, but distinctly audible, it came from directly beneath him, as though out of the very ground upon which he lay.

Buck Granger was no coward, but there are some things which, calmly accepted if not easily accounted for in the assurance and self-possession which one feels in daylight, seem to verge upon the supernatural in the darkness and mystery of night.

The hand which Buck Granger passed swiftly across his now wide staring eyes was as cold as ice. For a moment he lay there as though hypnotized. And then the moan was repeated, this time so subdued as to be scarcely audible, but all the more uncanny for that very fact. With a quick movement that brought him to his hands and knees, Buck literally dived across the black space to where the other three men lay, landing directly beside Tom Walton.

“Tom!” he whispered shrilly into the latter’s ear. “Tom! Wake up! It’s Buck Granger! There’s something queer going on around this shack!”

Tom, who had been partially aroused by the first mention of his name, came upright into a sitting posture as Granger spoke jerkily of the mystery at hand; and he sat up with such suddenness and force that his head, striking Buck directly under the chin, nearly dislocated the latter’s neck and as narrowly escaped cracking Tom’s skull.

“What is it? What’s the matter?” the young sergeant demanded, also in a hoarse whisper, as they both rubbed their respective injuries.

“Listen!” Buck responded; but there was no necessity, for just at that instant the moan was repeated for the third time, now as clear and distinct as the first time Buck had heard it.

“Great Scott, that’s wierd,” Tom exclaimed, almost involuntarily. “What is it? Who is it? Where does it come from?”

“I don’t know who or what it is,” Buck whispered back, “but it seemed to come right up out of the ground where I was asleep, and you’re right, it’s wierd enough.”

“When did you hear it first?” Tom asked in a low tone, at the same time cocking his ear in the darkness for a repetition of the strange sound.

“Just a moment ago—heard it twice,” answered Buck. “Let’s waken the others and make a light and see what we can find.”

Tom reached into his pocket and drew, forth an electric searchlight which he immediately switched on. Their first act was to squint around in the glare of the light into every crook and cranny of the little cow-shed, but there was nothing unusual to be found, nor was there any further sound.

“I’ve always heard that ghosts fade into thin air and cease all sound when a light appears,” said Tom, trying to speak lightly.

“There’s no such thing as a ghost, as you and I both know,” Buck responded, resenting anything that might tend to make him look foolish. “That groan came from a man, and whoever he is or wherever he is the fellow isn’t far away from where we are right now.”

“What’s the matter with you two, anyway,” demanded Ollie Ogden, suddenly sitting up and rubbing his eyes, and at the same time so disturbing Harper that he too, awakened.

“Wait a minute or two and you’ll know as much as we do,” Tom replied.

But they did not have to wait that long. The words had hardly died on Tom’s lips when something most resembling the sighing of wind through the bare branches of trees, but which all four knew to be a human sound, reached their ears. And just as Buck Granger had said, it seemed to come from directly out the ground, at the spot where he had been sleeping.

Tom took the pocket searchlight over to that part of the shed and began an examination. He laid his ear to the damp earth, but could hear nothing. Then playing the light over the ground, he got down upon his hands and knees for a closer examination. Standing around him and gazing over his shoulder, the other three carefully followed his every move.

He was moving around almost in a circle, when accidentally, in a quick turn, he kicked a section of the shed wall heavily with the heel of his boot. He drew up suddenly, and the other lads crowded closer to him.

“Didn’t that seem to you to have a peculiar sound?” he asked.

“It certainly did to me,” George Harper replied.

“Like tapping a rotten watermelon,” said Buck Granger, in language more descriptive than elegant.

“Sounded hollow, anyway,” put in Ollie Ogden.

“That’s just what I thought,” said Tom, and to verify their verdict he tapped the partition again. It gave off the same empty sort of sound.

“Ah, ha!” exclaimed George Harper, leaning over Tom’s shoulder, and examining the woodwork above the sergeant’s head. “I guess this explains it. Looks like some sort of a secret door.”

He had been tracing the outline of a scarcely perceptible crack which ran from the floor to a height of about three feet, then across for two more feet, where it joined another vertical one which paralleled the first. Also he had found what anyone might have taken for a knot-hole at first glance, but which closer examination showed to have been made, apparently for the purpose of pulling the thing open.

“Try it again,” Tom suggested, as George, with one finger crooked into the aperture, gave it a tug without any seeming result. “Try it again; I thought it moved a little.”

With considerable effort Harper managed to twist two fingers of his right hand into the hole, and again gave a sudden jerk; but the only result was a slight vibration, while George vigorously rubbed his two pained digits.

“Wait a minute,” Ollie suggested, and going across the shed he picked up a piece of iron shaped at the end like a stove poker. “Try this,” he suggested.

“Let somebody else do it,” said Harper. “My hand feels as though it was broken.”

Tom took the iron, fixed the end into the hole and gave a mighty yank. As the secret door gave way under his weight, Tom suddenly and unceremoniously and without advance preparation took a seat on the floor at the far side of the shed.

At any other time his fall might have caused some merriment, but no one paid attention to it now. They were too busy examining a little apparatus in the closet-like aperture in the wall of the shed, which now stood exposed to full view. The mechanism resembled, in fact was almost a replica, of the dial on the front of a combination safe. The only difference was that this disc was marked only with an S at the top, an O at the bottom, and with a line running part way around it, near the outer edge, with an arrow at the bottom end, showing that the small lever over the dial was always moved from the top downward to the right, and then upward on the other side.

“S and O,” Tom read off, gazing at the queer thing as he joined the others. “And it points to S now. Why, that seems to be clear. It means ‘shut’ and ‘open.’”

“If it’s connected up with any signalling apparatus a complete revolution of that lever also might sound an S.O.S.,” suggested Buck Granger.

“Or it might mean ‘slip out’ while the slippin’s good,” put in Ollie.

“Oh, it might mean any one of a thousand things, such as ‘stop orating’” George Harper spoke up, impatiently, “but I’m inclined to believe Tom’s right. Let’s try it, anyway.”

Tom was just reaching for the small lever when another suppressed moan, unquestionably from directly beneath their feet, arrested his hand.

“There’s someone down there under the ground,” said Tom, in an awed whisper. “I believe there’s some connection between that person and this thing here. I’m going to try it anyway. Suppose you fellows stand back there against the opposite wall, in case anything happens to me when I turn this lever. And Ollie, you hold the light so that it will be directly on the dial.”

Not knowing what to expect, the three youths stood with their backs against the opposite wall, staring at Tom’s hand as the fingers closed on the lever and he began turning it toward the mark O, in the direction the arrow indicated.

Slowly he pushed it round until the point was directly over the O. Tom stepped over to where the others were, and he was just in time. There was a sucking sound, such as is made by drawing one’s boot out of oozy mud, and then the ground where Buck Granger had slept began to move upward!

The lads stood huddled together. The ground, which proved to be but a very thin layer, gave way, and a trap door lifted itself slowly into the air.

Tom was the first to move. He stepped over and peered down into the hole.

“Great guns!” he gasped, in a quivering voice.

The others were at his side in an instant. The sight was a staggering shock to all.

There, on the bottom of a black cavern that apparently extended under the whole flooring of the cow-shed, lay two bodies. Both were in French uniforms. Obviously one man was dead. The other moved slightly and gave another low moan that showed he was alive, although not conscious. Three huge rats scampered away in fright as the light was thrown upon them.

“Ollie,” said Tom, again taking the leadership, “you get a surgeon as quickly as you can. We’ve got to get that fellow out, and save his life if possible.”

Without a word Ollie was gone on the errand directed, while Tom, holding to the hands of George Harper and Buck Granger, lowered himself into the subterranean prison, the floor of which was not more than five feet below that of the shed.

Tom turned the living man over so as to see his face. It was drawn in lines of suffering and fixed in an expression of absolute terror. The whole body was emaciated almost beyond belief.

“Poor fellow,” murmured Tom, as he placed one arm under the shoulders of the soggy and mildewed uniform. “Left here to go stark mad and starve to death. Probably heard death rattle of his companion here as the rats were gnawing at him. Ugh!”

The man weighed no more than an average boy of fifteen or sixteen years. Tom raised the body carefully, lifted it to the height of the shed floor, and into the hands of the two youths waiting there. Tom himself was just climbing out of the pit when Ollie and a surgeon entered.

“What have we got here?” the latter asked, as with businesslike precision he strode to the still form on the floor, the boys making way for him.

In a few brief words Tom explained—told how Buck Granger first had been awakened, then how all of them had heard the moans, and of the discovery of the secret switch, and then of the cavern and the bodies within.

As Tom spoke the surgeon cast a queer look at him, but an instant later he was working over the unconscious Frenchman, a hand on his pulse, his ear to his heart.

“Weak,” he announced at last, “mighty weak. If he survives it will be because you men reached him not a moment too soon. But at that he may be a hopeless lunatic. We can’t tell about that yet—especially when a man has gone through what this one evidently has.”

The surgeon again looked down at his patient. “Why,” he ejaculated suddenly, “he wears a major’s uniform—infantry, too.”

It was true. The ghastly ruin of a man that lay before them once had been a battalion commander in the French army.

“Discovered at last,” the surgeon murmured, more to himself than the others.

“What?” demanded Tom, quickly.

“The terrible torture prison that we all have heard about, but never knew how to locate.”

The surgeon paused for an instant as the unconscious man made a feeble movement.

“Unquestionably,” he continued, “this is the Hun chamber of horrors known throughout the Allied armies—the Death Dungeon.”