n an argumentative tone. "I'd rather stay
awake part of the night than all of it."

"Don't you even want to solve the mystery?" asked Chet, in an
aggrieved voice.

"Mystery--humph," grunted Mrs. Gilligan, feeling very brave and
disdainful in the bright sunshine. "I don't believe there's a bit of
mystery in the whole thing."

"Then what made the piano play?" Teddy insisted. "You said yourself that
you heard it."

"Oh, I heard it all right," said Mrs. Gilligan, helping herself to more
jam. "There isn't any doubt about that. But I have an idea what caused
it, all right."

"Oh, tell us," they cried eagerly.

But their chaperone shook her head determinedly while her lip became
still tighter.

"No, indeed I won't tell you," she said, adding with a little chuckle: "I
want to try it out myself first. For I know that if I told you young ones
about it you'd only laugh. And I don't like being laughed at."

"But we wouldn't laugh," Billie assured her earnestly. "Really,
Mrs. Gilligan, we'll promise on our word of honor not to so much as
even smile."

"Get out with your promises," said Mrs. Gilligan, relapsing into her
brogue. "I do be knowing you better. I'll try it to-night," she
added graciously, "and if it doesn't work I'll tell you about it in
the morning."

"I suppose here's where I spend another sleepless night," said Violet
dolefully, helping herself to more biscuits. "Oh, well, I'm getting so I
can do without sleep now."

"Well, you don't look as if you'd ever lost a wink in your life," said
Chet, glancing at her admiringly, for it was an open secret with the
boys and girls of North Bend that Chet rather especially liked tall,
dark, peace-loving Violet Farrington--perhaps because she was so much
like himself.

Violet blushed prettily at this complimentary remark, and the girls
looked at her teasingly.

"Who was it that said something or other was blind?" asked Laura
wickedly, and Violet kicked her under the table.

"Peace, my children," said Billie. "We're having enough trouble with
ghosts and things without starting a war among ourselves. Who'll have
some more jelly?"

There was a simultaneous shout of approval, and the jelly dish began its
fourth round of the table.

However, they did at last get through eating and wandered out on the
front porch, where Mrs. Gilligan could not scoff at their ideas, to
discuss the doings of the night before.

But it was only a little while later that Mrs. Gilligan