, yet was strangely unlike, the chugging of a motor car.

She sat absolutely still with every nerve tense, feeling chilly
and scared.

At last she could stand it no longer and, leaning over, touched Laura
gently on the arm.

"What's the matter?" cried the latter, starting up fearfully. At the same
moment Billie opened her eyes.

"That noise!" whispered Violet. "Listen!"

CHAPTER XVII

ONLY A BAT

The three girls sat quiet, every nerve tense, that same chilly sensation
creeping up their spines, and their hair beginning to stand on end.

Out there in that wilderness, at three o'clock in the morning, a noise
that sounded something like a motor car and yet was unlike anything they
had ever heard before, might have frightened more experienced people than
three fourteen-year-old girls.

"H-here it comes!" whispered Violet, clutching at Laura's arm, while
Laura in her turn clutched at Billie's. "It's coming closer! Oh,
girls--is it in the house?"

"Sh!" cried Billie. "It's a machine--it must be a machine--out on
the road."

"But in this forsaken place, in the middle of the night?" cried Laura,
beginning to shiver as though she were cold. "It--it can't be, Billie!"

"Sh-h," said Billie again. "Listen!"

The purring sound was coming closer, seemed almost in the house, it was
so near--Then came an awful thought to Billie. Could it really be in the
house? Was it possible that those awful stories about ghosts were true?

But no, the noise was passing on, getting softer, softer, dying off in
the distance.

"It--it must have been a machine," said Laura, beginning to laugh
hysterically. "Vi, what did you go and wake me up in the middle of the
night for just to hear an automobile? I was having such a lovely sleep."

"But I'm not so sure it was a motor car," insisted Violet stubbornly, the
spell of the dream still upon her. "It didn't sound like it."

"But it couldn't have been anything else," said Billie, trembling a
little with the reaction. "We heard it coming down the road, heard it
pass the house, and go on. It simply must have been a machine."

"Oh, all right," said Violet, adding with a little sigh: "Well, I guess
none of us will sleep any more to-night. I'm not even going to try."

"Well, I am," said Billie, leaning back and closing her eyes, yet knowing
that she was as wide awake as she had ever been in her life. "I don't see
any use in lying here and listening for things. Good night once more,
g