ll mystery. "You
Outdoor Girls are always doing something novel. What is it this time?"

"A winter camp!" they cried in chorus.

"List to the pretty maidens!" sung Will, mockingly, as he assumed a
theatrical attitude.

"Behave!" ordered his sister, whereat Will proceeded to contort himself
in various ways to the great amusement of the girls.

"That's fine!" exclaimed Mr. Blackford--"fine that you can go camping, I
mean--not Will's circus act. But I must apologize for coming in on you
this way. I happened to have some business in town, and as I received a
curious bit of news I thought you girls might be interested. It's about
my missing sister," he added, simply. "I've told you how I have been
searching for her.

"Perhaps I shouldn't bother you with my family troubles," he continued,
hesitatingly, "but, somehow, ever since you helped me out so in the
matter of that five hundred dollars, I have felt as though you did
really take an interest in me, as I do in you. And, as I haven't any
real folks of my own--so far," and he smiled, "naturally I come to you.
Shall I go on?"

The girls nodded. After making the acquaintance of the young man in the
manner related in our first volume, they had learned the queer fact of
Mr. Blackford having a sister of whom he had lost track. At one time he
hoped it might develop that she was the strange girl who fell out of the
tree, but it was not so. This girl, Carrie Norton, had, after spending
some time in Deepdale, departed to live with a distant relative.

Mr. Blackford had engaged a firm which made a specialty of locating
missing persons to look for his sister, but so far there had been no
result.

"And it doesn't look as though this were going to be very promising,"
the young man went on. "You know this searching firm has been delving
among my wood-pile relations, as I call them, looking for clues," he
went on. "They are getting all the old documents, bits of family
history, descriptions, and so on, that they can lay hands on. It all
helps, in a way, but we haven't had much luck so far. But you may be
interested in something that just came up, and you may be able to help
me.

"I've been traveling about, in connection with my business, and as I
knew I would 'make' this town to-night, I had all my mail sent here.
Imagine my surprise when I got to my hotel, a little while ago, to find
the most promising clue yet."

"What is it?" asked Betty, eagerly.

"I thought you might be