As Alice saw M. Paul she ran forward with a glad cry and clung to his arm.

"I've been so frightened," she trembled. "The man said you wanted me and I came at once, but, in the automobile, I felt something was wrong and—you know he is outside?" Her eyes widened anxiously.

"I know. Sit down here." He pointed to the table. "Does Pougeot know about this?"

She shook her head. "The man came for M. Pougeot first. I wasn't down at breakfast yet, so I don't know what he said, but they went off together. I'm afraid it was a trick. Then about twenty minutes later the same man came back and said M. Pougeot was with you and that he had been sent to bring me to you. He showed me your ring and——"

"Yes, yes, I understand," interrupted Coquenil. "You are not to blame, only—God, what can I do?" He searched the shadows with a savage sense of helplessness.

"But it's all right, now, M. Paul," she said confidently, "I am with you."

Her look of perfect trust came to him with a stab of pain.

"My poor child," he muttered, peering about him, "I'm afraid we are—in trouble—but—wait a minute."

Taking the candle, Coquenil went through the arched opening into the larger chamber and made a hurried inspection. The room was about fifteen feet square and ten feet high, with everything of stone—walls, floor, and arched ceiling. Save for the passage into the smaller room, there was no sign of an opening anywhere except two small square holes near the ceiling, probably ventilating shafts.

Around the four walls were logs piled evenly to the height of nearly six feet, and at the archway the pile ran straight through into the smaller room. The logs were in two-foot lengths, and as the archway was about four feet wide, the passage between the two rooms was half blocked with wood.

Coquenil walked slowly around the chamber, peering carefully into cracks between the logs, as if searching for something. As he went on he held the candle lower and lower, and presently got down upon his hands and knees and crept along the base of the pile.

"What are you doing?" asked Alice, watching him in wonder from the archway.

Without replying, the detective rose to his feet, and holding the candle high above his head, examined the walls above the wood pile. Then he reached up and scraped the stones with his finger nails in several places, and then held his fingers close to the candlelight and looked at them and smelled them. His fingers were black with soot.

"M. Paul, won't you speak to me?" begged the girl.

"Just a minute, just a minute," he answered absently. Then he spoke with quick decision: "I'm going to set you to work," he said. "By the way, have you any idea where we are?"

She looked at him in surprise. "Why, don't you know?"

"I think we are on the Rue de Varennes—a big hÔtel back of the high wall?"

"That's right," she said.

"Ah, he didn't take me away!" reflected M. Paul. "That is something. Pougeot will scent danger and will move heaven and earth to save us. He will get Tignol and Tignol knows I was here. But can they find us? Can they find us? Tell me, did you come down many stairs?"

"Yes," she said, "quite a long flight; but won't you please——"

He cut her short, speaking kindly, but with authority.

"You mustn't ask questions, there isn't time. I may as well tell you our lives are in danger. He's going to set fire to this wood and——"

"Oh!" she cried, her eyes starting with terror.

"See here," he said sharply. "You've got to help me. We have a chance yet. The fire will start in this big chamber and—I want to cut it off by blocking the passageway. Let's see!" He searched through his pockets. "He has taken my knife. Ah, this will do!" and lifting a plate from the table he broke it against the wall. "There! Take one of these pieces and see if you can saw through the rope. Use the jagged edge—like this. That cuts it. Try over there."

Alice fell to work eagerly, and in a few moments they had freed a section of the wood piled in the smaller chamber from the restraining ropes and stakes.

"Now then," directed Coquenil, "you carry the logs to me and I'll make a barricade in the passageway."

The word passageway is somewhat misleading—there was really a distance of only three feet between the two chambers, this being the thickness of the massive stone wall that separated them. Half of this opening was already filled by the wood pile, and Coquenil proceeded to fill up the other half, laying logs on the floor, lengthwise, in the open part of the passage from chamber to chamber, and then laying other logs on top of these, and so on as rapidly as the girl brought wood.

They worked with all speed, Alice carrying the logs bravely, in spite of splintered hands and weary back, and soon the passageway was solidly walled with closely fitted logs to the height of six feet. Above this, in the arched part, Coquenil worked more slowly, selecting logs of such shape and size as would fill the curve with the fewest number of cracks between them. There was danger in cracks between the obstructing logs, for cracks meant a draught, and a draught meant the spreading of the fire.

"Now," said M. Paul, surveying the blocked passageway, "that is the best we can do—with wood. We must stop these cracks with something else. What did you wear?" He glanced at the chair where Alice had thrown her things. "A white cloak and a straw hat with a white veil and a black velvet ribbon. Tear off the ribbon and—we can't stand on ceremony. Here are my coat and vest. Rip them into strips and—Great God! There's the smoke now!"

As he spoke, a thin grayish feather curled out between two of the upper logs and floated away, another came below it, then another, each widening and strengthening as it came. Somewhere, perhaps in his sumptuous library, De Heidelmann-Bruck had pressed an electric button and, under the logs piled in the large chamber, deadly sparks had jumped in the waiting tinder; the crisis had come, the fire was burning, they were prisoners in a huge, slowly heating oven stacked with tons of dry wood.

"Hurry, my child," urged Coquenil, and working madly with a piece of stick that he had wrenched from one of the logs, he met each feather of smoke with a strip of cloth, stuffing the cracks with shreds of garments, with Alice's veil and hat ribbon, with the lining of his coat, then with the body of it, with the waist of her dress, with his socks, with her stockings, and still the smoke came through.

"We must stop this," he cried, and tearing the shirt from his shoulders, he ripped it into fragments and wedged these tight between the logs. The smoke seemed to come more slowly, but—it came.

"We must have more cloth," he said gravely. "It's our only chance, little friend. I'll put out the candle! There! Let me have—whatever you can and—be quick!"

Again he worked with frantic haste, stuffing in the last shreds and rags that could be spared from their bodies, whenever a dull glow from the other side revealed a crack in the barricade. For agonized moments there was no sound in that tomblike chamber save Alice's quick breathing and the shrieking tear of garments, and the ramming thud of the stick as Coquenil wedged cloth into crannies of the logs.

"There," he panted, "that's the best we can do. Now it's up to God!"

For a moment it seemed as if this rough prayer had been answered. There were no more points in the barricade that showed a glow beyond and to Coquenil, searching along the logs in the darkness by the sense of smell, there was no sign of smoke coming through.

"I believe we have stopped the draught," he said cheerfully; "as a final touch I'll hang that cloak of yours over the whole thing," and, very carefully, he tucked the white garment over the topmost logs and then at the sides so that it covered most of the barricade.

"You understand that a fire cannot burn without air," he explained, "and it must be air that comes in from below to replace the hot air that rises. Now I couldn't find any openings in that large room except two little ventilators near the ceiling, so if that fire is going to burn, it must get air from this room."

"Where does this room get its air from?" asked Alice.

Coquenil thought a moment. "It gets a lot under that iron door, and—there must be ventilating shafts besides. Anyhow, the point is, if we have blocked this passage between the rooms we have stopped the fire from turning, or, anyhow, from burning enough to do us any harm. You see these logs are quite cold. Feel them."

Alice groped forward in the darkness toward the barricade and, as she touched the logs, her bare arm touched Coquenil's bare arm.

Suddenly a faint sound broke the stillness and the detective started violently. He was in such a state of nervous tension that he would have started at the rustle of a leaf.

"Hark! What is that?"

It was a low humming sound that presently grew stronger, and then sang on steadily like a buzzing wheel.

"It's over here," said Coquenil, moving toward the door. "No, it's here!" He turned to the right and stood still, listening. "It's under the floor!" He bent down and listened again. "It's overhead! It's nowhere and—everywhere! What is it?"

As he moved about in perplexity it seemed to him that he felt a current of air. He put one hand in it, then the other hand, then he turned his face to it; there certainly was a current of air.

"Alice, come here!" he called. "Stand where I am! That's right. Now put out your hand! Do you feel anything?"

"I feel a draught," she answered.

"There's no doubt about it," he muttered, "but—how can there be a draught here?"

As he spoke the humming sound strengthened and with it the draught blew stronger.

"Merciful God!" cried Coquenil in a flash of understanding, "it's a blower!"

"A blower?" repeated the girl.

M. Paul turned his face upward and listened attentively. "No doubt of it! It's sucking through an air shaft—up there—in the ceiling."

"I—I don't understand."

"He's forcing a draught from that room to this one. He has started a blower, I tell you, and——"

"What is a blower?" put in Alice.

At her frightened tone Coquenil calmed himself and answered gently: "It's like a big electric fan, it's drawing air out of this room very fast, with a powerful suction, and I'm afraid—unless——"

Just then there came a sharp pop followed by a hissing noise as if some one were breathing in air through shut teeth.

"There goes the first one! Come over here!" He bent toward the logs, searching for something. "Ah, here it is! Do you feel the air blowing through toward us? The blower has sucked out one of our cloth plugs. There goes another!" he said, as the popping sound was repeated. "And another! It's all off with our barricade, little girl!"

"You—you mean the fire will come through now?" she gasped. He could hear her teeth chattering and feel her whole body shaking in terror.

Coquenil did not answer. He was looking through one of the open cracks, studying the dull glow beyond, and noting the hot breath that came through. What could he do? The fire was gaining with every second, the whirling blower was literally dragging the flames toward them through the dry wood pile. Already the heat was increasing, it would soon be unbearable; at this rate their hold on life was a matter of minutes.

"The fire may come through—a little," he answered comfortingly, "but I—I'll fix it so you will be—all right. Come! We'll build another barricade. You know wood is a bad conductor of heat, and—if you have wood all about you and—over you, why, the fire can't burn you."

"Oh!" said Alice.

"We'll go over to this door as far from the passageway as we can get. Now bring me logs from that side pile! That's right!"

He glanced at the old barricade and saw, with a shudder, that it was already pierced with countless open cracks that showed the angry fire beyond. And through these cracks great volumes of smoke were pouring.

Fortunately, most of this smoke, especially at first, was borne away upward by the blower's suction, and for some minutes Alice was able to help Coquenil with the new barricade. They built this directly in front of the iron door, with only space enough between it and the door to allow them to crouch behind it; they made it about five feet long and three feet high. Coquenil would have made it higher, but there was no time; indeed, he had to do the last part of the work alone, for Alice sank back overcome by the smoke.

"Lie down there," he directed. "Stretch right out behind the logs and keep, your mouth close to the floor and as near as you can to the crack under the door. You'll have plenty of cool, sweet air. See? That's right. Now I'll fix a roof over this thing and pretty soon, if it gets uncomfortable up here, I'll crawl in beside you. It's better not to look at the silly old barricade. Just shut your eyes and—rest. Understand little friend?"

"Ye-es," she murmured faintly, and with sinking heart, he realized that already she was drifting toward unconsciousness. Ah, well, perhaps that was the best thing!

He looked down at the fair young face and thought of her lover languishing in prison. What a wretched fate theirs had been! What sufferings they had borne! What injustice! And now this end to their dream of happiness!

He turned to his work. He would guard her while life and strength remained, and he wondered idly, as he braced the overhead logs against the iron door, how many more minutes of life this shelter would give them. Why take so much pains for so paltry a result?

He turned toward the barricade and saw that the flames were licking their way through the wall of logs, shooting and curling their hungry red tongues through many openings. The heat was becoming unbearable. Well, they were at the last trench now, he was surprised at the clearness and calmness of his mind. Death did not seem such a serious thing after all!

Coquenil crawled in behind the shelter of logs and crouched down beside the girl. She was quite unconscious now, but was breathing peacefully, smilingly, with face flushed and red lips parted. The glorious masses of her reddish hair were spread over the girls white shoulders, and it seemed to M. Paul that he had never seen so beautiful a picture of youth and innocence.

Suddenly there was a crumbling of logs at the passageway and the chamber became light as day while a blast of heat swept over them. Coquenil looked out around the end of the shelter and saw flames a yard long shooting toward them through widening breaches in the logs. And a steady roar began. It was nearly over now, although close to the floor the air was still good.

He reflected that, with the enormous amount of wood here, this fire would rage hotter and hotter for hours until the stones themselves would be red hot or white hot and—there would be nothing left when it all was over, absolutely nothing left but ashes. No one would ever know their fate.

Then he thought of his mother. He wished he might have sent her a line—still she would know that her boy had fallen in a good cause, as his father had fallen. He needn't worry about his mother—she would know.

Now another log crumbled with a sharp crackling. Alice stirred uneasily and opened her eyes. Then she sat up quickly, and there was something in her face Coquenil had never seen there, something he had never seen in any face.

"Willie, you naughty, naughty boy!" she cried. "You have taken my beautiful dolly. Poor little Esmeralda! You threw her up on that shelf, Willie; yes, you did."

Then, before Coquenil could prevent it, she slipped out from behind the shelter and stood up in the fire-bound chamber.

"Come back!" he cried, reaching after her, but the girl evaded him.

"There it is, on that shelf," she went on positively, and, following her finger, Coquenil saw, what he had not noticed before, a massive stone shelf jutting out from the wall just over the wood pile. "You must get my dolly," she ordered.

"Certainly, I'll get it," said M. Paul soothingly. "Come back here and—I'll get your dolly."

She stamped her foot in displeasure. "Not at all; I don't like this place. It's a hot, nasty place and—come"—she caught Coquenil's hand—"we'll go out where the fairies are. That's a much nicer place to play, Willie."

Here there came to M. Paul an urging of mysterious guidance, as if an inward voice had spoken to him and said that God was trying to save them, that He had put wisdom in this girl's mouth and that he must listen.

"All right," he said, "we'll go and play where the fairies are, but—how do we get there?"

"Through the door under the shelf. You know perfectly well, Willie!"

"Yes," he agreed, "I know about the door, but—I forget how to get it open."

"Silly!" She stamped her foot again. "You push on that stone thing under the shelf."

Shading his eyes against the glare, Coquenil looked at the shelf and saw that it was supported by two stone brackets.

"You mean the thing that holds the shelf up?"

"Yes, you must press it."

"But there are two things that hold the shelf up. Is it the one on this side that you press or the one on that side?"

"Dear me, what an aggravating boy! It's the one this side, of course."

"Good! You lie down now and I'll have it open in a jiffy."

He started to force Alice behind the shelter, for the heat was actually blistering the skin, but to his surprise he found her suddenly limp in his arms. Having spoken these strange words of wisdom or of folly, she had gone back into unconsciousness.

Coquenil believed that they were words of wisdom, and without a moment's hesitation, he acted on that belief. The wall underneath the shelf was half covered with piled-up logs and these must be removed; which meant that he must work there for several minutes with the fierce breath of the fire hissing over him.

It was the work of a madman, or of one inspired. Three times Coquenil fell to the floor, gasping for breath, blinded by the flames that were roaring all about him, poisoned by deadly fumes. The skin on his arms and neck was hanging away in shreds, the pain was unbearable, yet he bore it, the task was impossible, yet he did it.

At last the space under the shelf was cleared, and staggering, blackened, blinded, yet believing, Paul Coquenil stumbled forward and seized the left-hand bracket in his two bruised hands and pressed it with all his might.

Instantly a door underneath, cunningly hidden in the wall, yawned open on a square black passage.

"It's here that the fairies play," muttered M. Paul, "and it's a mighty good place for us!"

With a bound he was back at the shelter and had Alice in his arms, smiling again, as she slept—as she dreamed. And a moment later he had carried her safely through flames that actually singed her hair, and laid her tenderly in the cool passage. And beside her he laid the baron's diary!

"And a moment later he had carried her safely through the flames."

Then he went back to close the door. It was high time, for the last obstructing logs of the old barricade had fallen and the chamber was a seething mass of fire.

"I feel pretty rotten," reflected Coquenil with a whimsical smile. "My hair is burned off and my eyebrows are gone and about half my skin, but—I guess I'll take a chance on a burn or two more and rescue Esmeralda!"

Whereupon he reached up inside that fiery furnace and, groping over the hot stone shelf, brought down a scorched and battered and dust-covered little figure that had lain there for many years.

It was the lost dolly!