"My p'ayhouse all gone!" he cried. "Trouble's house all goned away!"

It was true. Not a trace of his playhouse was left! In the night someone
or something had taken the blue stones away.

CHAPTER XVIII

IN THE CAVE

Trouble felt very bad about his playhouse of blue stones which had been
taken away. He was only a little fellow, and when he had gone to so much
work, building up what looked like a fairy castle, he surely thought he
would find it where he left it at night to have it to play with the next
morning. But it was gone.

"All goned," sobbed Trouble.

"Isn't it funny, though?" said Teddy. "Mine is all right, and so is
yours, Jan, and Hal's, too. They just spoiled Trouble's."

"Maybe it was Nicknack," suggested Jan. "He might have got loose in the
night and knocked it down. But he didn't mean to I guess, for he's a
good goat."

"It couldn't have been Nicknack," declared Hal.

"Why not?" asked Ted. "Didn't he fall down into the big hole when
Trouble led him to it?"

"Yes, but Nicknack is there in his stable. He isn't loose at all, and
he'd have to be loose to come here and knock over Trouble's playhouse.
The goat is tied fast just where he was last night."

So Nicknack was; and Grandpa Martin, who was the first one up in the
camp that morning, said the goat was lying quietly down in his stable
when he went to give him a drink of water. So it couldn't have been
Nicknack.

"Anyhow, Trouble's blue-stone castle wasn't just knocked down," went on
Hal, "it's gone--every stone is gone. Somebody took 'em!"

Jan and Ted noticed this for the first time. When Trouble had called out
that his playhouse was gone they had thought he meant it was just
knocked over. But, instead, it was gone completely. Not a blue stone was
left.

And, strangely enough, none of the other three castles was touched. Hal
had built quite a large one, but not a stone had been taken from it.

"Where my p'ayhouse?" asked Trouble, looking all about. "I want my
p'ayhouse."

"We'll find it for you," promised Jan, though she did not know how she
was going to do it. Perhaps Hal could think of a way. Hal was older than
Jan and Ted.

"What's the matter, Curlytops?" asked Mother Martin as she came out of
the tent. "Has anything happened? Why is Trouble crying? Did he get
hurt?"

"No, but someone took away his nice blue stone castle," explained Jan,
and she and the others took turns telling what had happened.

"It is queer," said