“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!”