One night, when the four chums were at Fenn"s house, getting ready some things, and talking of the fun they expected to have, there came a knock on the front door. As the boys were the only ones downstairs, Fenn volunteered to answer it.
"Though I don"t know who can be calling at this hour," he remarked, for it was nearly ten o"clock. He opened the door, and his startled exclamation brought his chums to his side.
"There"s no one here!" cried the stout lad, "but I was sure I heard a knock--didn"t you?"
"Sure," replied Bart, and the others nodded. "There has been some one here," went on Bart. "See the footprints in the snow. It"s snowed since we came. Some one ran up, knocked, and ran away again."
"I wonder what for?" murmured Fenn, looking up and down the deserted street. "Probably a joke. Maybe it was Sandy Merton."
"Whoever it was, he left something," said Frank, suddenly.
"What?" asked Fenn.
"This letter," answered Frank, picking up a missive from the doorstep.
The white envelope, so much like the snow, had not at first been noticed.
"Bring it in and see what it says," proposed Bart, and soon, under the light of the gas in the dining-room, the boys were perusing the strange missive.
"It"s to me," said Fenn, as he rapidly scanned it. "But what in the world does it mean? And it has no signature. Listen to this fellows,"
and he read:
""MR. FENN MASTERSON,
""Dear Sir:--I understand you have quite a collection of mud turtles. Would you be willing to part with them? I mean for a consideration, of course. If you would kindly communicate with me. I will pay you a good price for all the turtles you have. But I must make this stipulation, which, at first may seem odd to you. But I have a reason for it. I can not meet you personally.
If you are willing to sell your turtles will you write a note to that effect, and leave it in the dead sycamore tree on the edge of Oak Swamp? That is the only way in which you can communicate with me. Kindly let me hear from you soon.""
As Fenn had said, there was no signature. He turned the strange letter over and looked at the back. It was blank.
"Well, wouldn"t that jar you!" exclaimed Bart, as he took the note from Fenn"s hand.
CHAPTER IX
OFF TO CAMP
"This must be a joke," remarked Fenn, at length, after he had once more read the note. "Sandy Merton, or some of the other fellows, who want to have some fun with us, wrote that."
"I think not," said Frank, thoughtfully.
"Why?" inquired Ned.
"Some man wrote that," went on Frank. "That"s no boy"s handwriting.
There"s too much character to it. What are you going to do about it, Fenn?"
"Nothing, I guess. Of course, I"d sell my turtles and things, if I got a chance, for I think I"m going to collect different kinds of wood now, and----"
"What did I tell you?" interrupted Ned triumphantly. "I knew Fenn"s fad wouldn"t last much longer."
"It would, if we weren"t going camping," declared the stout youth, with vigor. "Only when I"m away there"ll be n.o.body to look after the things.
Mother is afraid to feed "em, and dad won"t, so if I had a good chance to get rid of "em I"d do it. Only I wouldn"t do business with a fellow like this, who doesn"t sign his name, and who wants me to act as if I was leaving money in response to a black-hand note. I"ll not pay any attention to it."
"I would, if I were you," said Frank, quietly, but with some determination.
"You would?" asked Bart, in some surprise.
"Sure. I think there"s something back of this," went on Frank. "If I were Fenn I"d enter into a correspondence with him, and try to find out what was at the bottom of it."
"What do you think it is?" asked Ned. "Let"s make another examination of the letter, detective style, and see what we can deduce from it."
"I think the man who wrote that letter is the same man we have met several times--the mysterious stranger who entered the school--the man who stole the diamond bracelet," spoke Frank, quickly.
"Then if you"ve got it all figured out, we don"t need to puzzle over this letter," decided Ned.
"Oh, I don"t say I"m altogether right," came from Frank quickly. "That"s only one theory."
"And I think it a good one," added Bart. "Fenn, suppose you answer this letter, and leave your reply in the dead sycamore tree."
"What shall I say?" asked the heavy-weight chum.
"Oh, you don"t need to be specific. Say you don"t like to do business this way, that you prefer to meet the writer. Then we"ll leave the letter in the tree, hide, and nab him when he comes for it."
"Good!" cried Ned. "That"s the stuff. Regular detective business, fellows. Come on, Fenn, write the letter."
"I think that would be a good plan," commented Frank, who, being more sober-minded than his chums usually were, often said the final word when some scheme was afoot. "If the writer wants to resort to such tactics as leaving an anonymous letter on the doorstep, we can retaliate by playing the spy on him. Get busy, Fenn."
"When shall we leave it in the tree?" asked the stout lad.
"To-morrow," answered Bart promptly. "We haven"t any too much time before going to camp. We"ll try to catch him to-morrow, and maybe we can solve the mystery of the diamond bracelet."
It took some time to compose a letter to the satisfaction of all four lads, as each one had some suggestion to make, but it was finally done, and enclosed in a strong, manilla envelope, ready to be left in the dead sycamore tree. Then the chums planned to go to Oak Swamp the next afternoon, early.
The appointed time found them at the place, and, as they came in sight of the tree, they adopted precautionary tactics previously agreed upon.
"For," Bart explained, "we want to catch that man, and we"ve got to go about it right. He"s given us the slip a number of times. Now, naturally, he"ll expect us to-day, and he"ll be in hiding somewhere near the tree.
Look around carefully, and see if we can"t spot him before we deposit the letter."
Accordingly, the lads made a cautious approach, but there was no sign of a man, or any one else near the big tree. The approach to the swamp appeared deserted, and on that afternoon, with a dull, leaden sky overhead, and a mournful wind sighing through the trees, Oak Swamp was anything but a cheerful place.
"It"s going to snow," observed Ned, as they walked slowly on toward the tree.
"Keep quiet," advised Bart, in a sharp whisper. "The man may be in hiding."
There were patches of snow on the ground about the sycamore, but an examination of them did not disclose any human footprints, though there were squirrel and rabbit tracks which gave the boys hope that they would get plenty of game when they went to their winter camp.
"He hasn"t been here," was Fenn"s opinion, as he took his letter and stuck it in a conspicuous place in a crack in the bark.