The other – and more important mystery – met Dan and Billy when they arrived home that very afternoon. The strange boy that Billy had knocked down the evening before, had disappeared.
“When we got up this morning, after you boys had gone,” explained their father, “that fellow had skedaddled. What do you think of that? And without a word!”
“Then Money Stevens may have seen him over by Island Number One!” cried Billy.
“It looks so,” admitted Dan. “I didn’t think there could be two chaps who couldn’t talk, in the neighborhood.”
“That’s not all, boys,” cried Carrie Speedwell. “Just see what little ’Dolph picked up.”
She presented a crumpled slip of paper for Dan and Billy to read.
“’Dolph found it right there beside the bed that strange boy slept on. He must have dropped it. See how it reads, Dan?”
Dan read the line scrawled on the paper, aloud:
“Buried on the island. Dummy will show you the spot.”
There was no signature, nor address – just the brief line. What it could refer to – what thing was buried, and on what island, was hard to understand. Only, it was quite certain that the “Dummy” referred to was the youthful stranger who could not talk English understandably.
“I am awful sorry he went away without his breakfast,” sighed Mrs. Speedwell. “And he didn’t look half fed, at best. It is too bad.”
“He’ll have a fine time living over on Island Number One at this season,” whispered Billy to Dan.
“Don’t let mother hear you,” replied the older boy, quickly. “She’d only worry.”
“Better let ‘Dummy’ do the worrying,” chuckled Billy.
“Well! it’s mighty odd,” said Dan, shaking his head. “And I really would like to know what’s buried on the island.”
“So would I,” said Billy. “Treasure – eh?”
“You’ve got treasure on the brain, boy,” grinned the older youth. “You’re getting mercenary. Haven’t you got wealth enough? We’re capitalists.”
“Yes – I know,” said Billy, nodding. “But I wonder if we’ve got money enough to get us the fastest iceboat that’s going to be raced on the Colasha this winter?”
“Ah! now you’ve said it,” agreed Dan. “But it isn’t going to be money that will get us that boat. We’ve got to learn something about iceboat building as well as iceboat sailing.”
“Huh! that blamed little wisp, Barry Spink,” grunted Billy.
“What about him now?” asked Dan, laughing.
“As inconsequential as he is, he’s got the whole town ‘bug’ on iceboating. He’ll be all swelled up like a toad.”
“We should worry!” returned Dan, with a shrug of his broad shoulders.
CHAPTER IV
THE “FLY-UP-THE-CREEK”
Mildred Kent, the doctor’s daughter, and her closest friend, Lettie Parker, halted the Speedwells at the close of school the next day. Mildred was a very pretty girl and Dan thought she was just about right. As for the sharp-tongued Lettie, she and Billy appeared to be always quarreling – in a good-natured way.
“We want to know what’s in the wind, boys?” demanded Mildred, her pretty face framed by a tall sealskin collar and her hands in a big shawl muff.
“There’s snow in this wind,” replied Billy, chuckling, for a few sharp flakes were being driven past the quartette as they stood upon the corner.
“Aren’t you smart, Billy Speedwell!” scoffed the red-haired Lettie. “Doesn’t it pain you?”
“You bet it does!” agreed Billy, promptly. “But they tell me that you suffer a deal yourself, Miss Parker, from the same complaint.”
“Now, children! children!” admonished Mildred. “Can’t you be together at all without scrapping?”
“And what about the wind, Mildred?” asked Dan.
“You boys were all down to the Boat Club last night, I hear. What is doing?”
“Aw, don’t tell ’em, Dan!” urged Billy, as though he really meant it. “They’ll want to play the part of the Buttinsky Sisters– you know they will!”
“I like that!” gasped Lettie, clenching her little gloved fist. “Oh! I wish sometimes I was a boy, Billy Speedwell!”
“Gee, Lettie! Isn’t it lucky you’re not?” he gasped. “There’d be no living in the same town with you. I like you a whole lot better as you are – ”
Dan and Mildred laughed, but Lettie was very red in the face still, and not at all pacified, as she declared:
“I believe I’d die content if I could just trounce you once – as you should be trounced!”
“Help! help! Ath-thith-tance, pleath!” begged Billy, keeping just out of the red-haired girl’s reach. “If you ever undertook to thrash me, Lettie, I know I’d just be scared to death.”
“Come now,” urged Mildred. “You are both delaying the game. And it’s cold here on the street corner. I want to know.”
“And what do you want to know, Miss?” demanded Billy.
“Why, I can tell you what we did last evening, if that’s what you want to know, Mildred,” said Dan, easily. “There’s nothing secret about it.”
“You can’t be going to plan any boat races this time of year?” exclaimed Lettie. “The paper says we’re going to have a hard winter and the Colasha steamboat line has laid off all its hands and closed up for the season. They say the river is likely to be impassable until spring.”
“That’s all you know about it,” interposed Billy. “We just did agree to have boat races on the river last evening. Now, then! what do you think?”
“I think all the Riverdale boys are crazy,” returned Lettie, promptly.
“What does he mean, Dan?” asked Mildred.
“Poof! Boat racing! Likely story,” grumbled the red-haired girl.
“Now, isn’t that the truth, Dan?” demanded Billy, but careful to circle well around Miss Parker to put his brother and Mildred between himself and the county clerk’s daughter.
“As far as it goes,” admitted Dan, chuckling. “But he doesn’t go far enough. We did talk some about having boat races – iceboat races.”
“Oh, ho!” cried Lettie. Her eyes flashed and she began to smile again. “Iceboats, Dannie? Really?”
“But I thought they were so dangerous?” demurred Mildred, rather timidly. “Didn’t Monroe Stevens and somebody else almost get drowned yesterday morning trying out an iceboat?”
“’Deed they did,” admitted Billy. “But the river wasn’t fit.”
“And you boys got them out of the water, too!” exclaimed Lettie, suddenly. “I heard about it.”
“Somebody had to pull ’em out, so why not we?” returned Dan quickly, with perfect seriousness.
“And you boys are going to build another boat?” asked Mildred.
“A dozen, perhaps,” laughed Billy.
“We’ll build one if nothing happens to prevent – Billy and I,” said Dan. “And if the interest continues, and there are enough