They did not light a fire in this, however, preferring to camp outside, for the cabin was musty and damp and the floor had given way in many places. Joe declared that it was certain to be infested with rats, and they could see how the creatures had gnawed the timbers. Instead, they established comfortable quarters outside the abandoned hut, and sat late around the fire, talking over their strange quest and the ill fortune of the snowstorm which had overtaken them.
It was just about as they were getting ready to turn in that Jack, who was sitting nearest the hut, started and turned pale. He held up one hand to command attention, and then he cried out:
“Gracious! Hark at that! What is it?”
What was it, indeed? Not the cry of the wolf pack, although that had come closer. Nor did it resemble anything else earthly. It was a booming sound like that produced by a giant bass fiddle and appeared to come from the air.
Old Joe crossed himself as he heard it.
“Sacre!” the boys heard him exclaim.
Again came the booming sound. It appeared to fill the air, to come from all directions. Mingled with it there burst suddenly on their ears a series of appalling shrieks, which also seemed to come from above.
Startled beyond power of controlling themselves, the boys jumped to their feet.
“It’s there! Up in the air!” cried Tom excitedly.
“But what can it——” began Jack, but he broke off suddenly. Into his mind, as well as into his brother’s, and, to judge by his expression, old Joe’s, there had burst simultaneously a sudden explanation.