n
never before in her life received two such letters. Both were
anonymous. The first one that she opened aroused enough curiosity to
"unsettle" her. She thought she knew whom it was from--those ingenious
Boy Scouts of Spring Lake--perhaps it was written by cousin Clifford
himself. It was just like him. He was a natural leader among boys, and
often up to mischief of some sort. Marion was sure he was one of the
prime movers of the Scout invasion of Hiawatha Institute.

But the next letter was the real thriller, or rather cold chiller. She
knew very well what it meant. From the point of view of the writer it
meant "business," a threat well calculated to work terror in her own
heart and the heart of every other member of Flamingo Fire. It was a
threat couched in direful words, warning her and her friends not to go
to Hollyhill on their charity mission, as announced, and predicting
serious injury if not death to some of them. It was signed with a
skull and cross-bones.

* * * * *

CHAPTER IV.

STUDYING THE MYSTERY.

Is there any wonder that Marion Stanlock, after reading letter No. 2
was seriously in doubt as to whether No. 1 was from the Scouts who had
promised another surprise for the Camp Fire Girls in the near future?
Judge for yourself--here is No. 1:

Something Doing Soon
Look Out
SOMETHING DOING SOON
LOOK OUT
=SOMETHING DOING SOON
LOOK OUT!=

That was all. The second letter read thus:

"Miss Stanlock: This is to serve you with warning not to take your
friends with you to Hollyhill this vacation to work among the poor
families of the striking miners. We know that move of yours is
inspired by the rankest hypocrisy, that you have no genuine desire to
do anything for our starving families. This move of yours, we know,
was planned by that villainous father of yours to cloud the big issue
of our fight. If you do carry out your plans, some of you are liable
to get hurt, and it need not surprise anybody if some of you never get
back to Westmoreland alive.

Go Slow! Be Careful! Look Out!"

Marion was not easily panic-stricken, but it is of the nature of a
truism to say that this letter applied the severest test to her
nerves. That the writer was in deep earnest she had no reason to
doubt. She had read of so many crimes preceded by threatening letters
of this sort that the suggestion did not come to her to regard this
one lightly