"Is it a dog?" asked Bobby, almost in a whisper, as for a third time the howl sounded.
"A dog barks, doesn't it? That doesn't sound like a dog, Bobby," said Betty. "I heard one out West. I do believe it is one!"
"One what?" cried Bobby, almost shaking her in alarm and impatience.
"A wolf. It sounds just like a wolf. Oh, Bobby! suppose there should be a pack of wolves in these hills and that they should attack this train?"
"Wolves!" shrieked Bobby. "Wolves! Then me for in-doors! I am not going to stay here and be eaten up by wolves."
As she turned to dive into the tunnel there was a sharper and more eager yelp, and a shaggy animal came to the edge of the bluff to their left and, without stopping an instant, plunged down through the drifts toward the two girls where they stood on the hard-packed snow at the mouth of the tunnel.
"It is a wolf!" wailed Bobby, and immediately disappeared, head first, down the hole in the snow drift.