boarded it. Then began a chatter of girl voices—happy, spirited, witty, and promising to continue thus to the end of the journey, or until their kaleidoscopic subjects of conversation were exhausted.

Every thrilling detail of the evening before was gone over, examined, given its proper degree of credit, and filed away in their memories for future reference. There was more catching of breath, more cheering, more clapping of hands; but no mock jeers, now that the boys were absent, as the events of the Boy Scouts' invasion and the many incidental and brilliant results were recalled and repictured.

"I wonder what Harry Gilbert meant when he said some of them were planning another surprise nearly as thrilling as the one they sprung last night," said Azalia Atwood, with characteristic excitable expectation. "He addressed himself to you, Marion, when he said it; and he's a close friend of your cousin, Clifford Long. Whatever it is, I bet anything it will fall heaviest on this Camp Fire when it comes."

"Maybe it was just talk, to get us worked up and looking for something never to come," suggested Ethel Zimmerman. "It would be a pretty good one for the boys to get us excited and looking for something clear up to April 1, and then spring an April fool joke, something like a big dry goods box packed with excelsior."

"Oh, but that wouldn't measure up to expectations," Ruth Hazelton declared. "It wouldn't be one-two-three with what they did last night, and they promised something just about as interesting."

"You don't get me," returned Ethel. "The dry goods box filled with excelsior would be the anti-climax of wondering expectations."

"You're too deep for a twentieth century bunch of girls, Ethel," Hazel Edwards objected. "That might easily be mistaken for the promised big stunt. They might compose a lot of ditties and mix them up with the packing, something like this:

"Very clever, indeed, only it sounds like an impossible combination of Alice in Wonderland and an old maid," said Harriet Newcomb, with a toss of her head. "I'm surprised at you, Hazel, for suggesting such a thing. If the boys should put over anything like that, we'd break off diplomatic relations right away. If they wanted to call us a lot of rummies, they couldn't do it as effectively by the use of direct language. Cleverness usually makes a hit with its victims, unless it contains an element of contempt."

"That is really a brilliant observation," announced the Guardian who had been listening with quiet interest to the spirited conversation. "Continued thought along such lines ought to result in a Keda National Honor for you, Harriet."

"I'll agree to all that if Harriet will take back what she said about my being an old maid," said Hazel with mock dignity.

"I didn't call you an old maid, my dear," denied the impromptu poet pertly. "I merely said, or meant to say, that the idea you expressed might better be expected from an old maid, although I doubt if many old maids could have expressed it as well as you did."

"Girls, Girls, are you going to turn our vacation into a two-weeks repartee bee?" Marion broke in with affected desperation. "If you do, you will force your hostess to go way back and sit down, and that wouldn't be polite, you know. By the way, if you'll excuse me I'll do that very thing now for another reason. I've got two letters in my hand bag that I forgot all about. I'm going to read them right now. You girls are making too much chatter. I can't read in your midst."

So saying, Marion retired to a chair just far enough away to lend semblance of reality to her "go way back and sit down" suggestion, and settled back comfortably to read the two missives that arrived with the last evening's mail at the Institute.

"Settled back comfortably"—yes, but only for a short time. Marion 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.

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. Although there was no common basis for comparing the handwriting of the two missives, one being lettered in Roman capitals and the other in ordinary script, nevertheless she quickly dismissed the first suspicion that letter No. 1 was written by Clifford Long or some other Scout of Spring Lake academy. Both ended with the words "Look Out." Plainly this was a result of carelessness on the part of the writer. Evidently he had planned to cause her to believe that the two letters were written by different persons, for he had taken the pains of differentiating the superscriptions on the envelopes as well as the contents within.

But now the question was, What should she do? It was no more than fair and just for her to inform the girls what they might expect if they attempted to carry out their original plan, but what method should she pursue to convey to them this information? She might go at the matter bluntly and create something of a panic; then again she might so handle it that the best possible result could be obtained in a quiet and orderly manner.

Marion felt in this crisis that a great responsibility rested on her to handle the problem with all the skill and intelligence at her command. She longed for the counsel of an older and more experienced head, but there was none present, except Miss Ladd, the Guardian