“Well, I wish we could find out what it is,” sighed Billie, as they started upstairs again.  “This staying awake all night isn’t very much fun.”

“But isn’t it strange,” asked Laura, stopping on the landing and looking back at them, “that both the piano and the motor should start again on the same night?”

“Yes, it is, rather,” said Chet, adding seriously:  “I wonder if there could really be any connection between the two.”

“There’s no use wondering, that I can see,” said Mrs. Gilligan, preparing to send them off to their respective bedrooms.  “I think the best thing we can do is not to notice them any more.  Perhaps the ghosts will get tired, if they find they don’t worry us,” this last with a chuckle.

“Well, but they do worry us,” said Violet plaintively.  “Every time I hear that piano, I just about die of fright.”

“Listen,” commanded Billie, and as they listened they heard it again!  The ghost, or whatever it was, was surely making a joke of them that night!

As soon as the boys could recover from their surprise they tumbled down the stairs, tripping over each other in their hurry, while the girls followed more slowly.

But again the noise stopped abruptly, and when they entered the room there was nothing to be seen or heard.

“Say, this thing is making me mad!” cried Ferd, glaring at the old piano as though it were the offender.  “I don’t mind meeting an honest-to-goodness ghost, but I’ll be hanged if I’ll let him laugh at me!”

“I don’t see how you’re going to help it,” said Teddy.  “Come on, fellows, it’s pretty nearly morning, and we can decide then what we’ll do to catch Mr. Ghost.  I’m so sleepy I’m apt to fall asleep on my feet.”

So they went upstairs again, feeling rather miserable and dragged out with excitement, and crawled into bed.

“If this thing keeps up much longer, I’ll just be a wreck, that’s all,” groaned Laura, and almost immediately she fell asleep.

After a little while of staring into the dark, Billie and Violet followed her example, and once more there was quiet in the old house.

Nothing more disturbed them, but they woke the next morning, tired and cross and with a decidedly “morning after” feeling.

“I don’t want to get up,” complained Violet, turning restlessly in bed and punching her pillow.  “I can’t get more than one eye open.”

“Shall we send for the doctor?” asked Billie, regarding her sleepily.  “That sounds like a serious complaint.”

“Humph, I don’t need a doctor,” grumbled Violet.  “I can prescribe for my case better than he could.  What I need is a rest cure.”

“So say we all of us,” echoed Laura sleepily.  “I’m going to take another nap, girls, and if anybody dares to wake me up, I’ll throw my hair brush at them.”

“I’m going to get up,” decided Billie.  “I’ll only get a headache lying here.”

“Well, I hope you enjoy yourself,” said Laura, and settled herself in a still more comfortable position.