"Halt!"

At the command the scouts came to a stop. They had been gradually concentrating as they pushed forward, so that when this halt was made they formed half a circle, and each fellow was almost touching elbows with the next in line.

Just before them, even though pretty well concealed by the foliage of the bushes, they could make out what appeared to be a rough shack.

No other name would apply, for it was clumsily built out of odds and ends of boards, secured at the mill, no doubt, together with sods, a heap of stones, some mud that had hardened until it resembled mortar; and, finally, a roof thatched with straw, much after the style the boys had seen in pictures of foreign cottages in Switzerland, France, and Italy.

"Say," observed Red, who found it unusually hard to keep from expressing his views, "I don't believe there are any kiyi dogs around here, fellows."

"Don't seem like it," remarked another, doubtless breathing a sigh of relief at the improved prospect.

"Sure we'd have heard them give tongue," observed Toby, advancing boldly to look in through the opening at the side of the shack, and which doubtless served the purpose of a window.

"Careful, Toby; go slow," called out Elmer; for there could be no telling what sort of a storm the appearance of the boys in khaki might raise within the shanty.

An intense silence followed. Every fellow could feel his heart pounding against his ribs like a trip hammer, and he wondered whether the sound were loud enough to betray his nervous frame of mind to his companions, never dreaming that they were all in the same box.

A red squirrel in a tree overhead, that had been observing all these doings with round-eyed wonder, began to chatter and scold. A little striped chipmunk sat up on a neighboring stump and took note.

"Nobody home, fellers," called out Toby, after he had apparently stared in through that opening for more than a full minute.

Some of the scouts looked relieved; others frowned as if disgusted. This sort of thing might be all very well, but it did not seem to be taking them any closer to the rescue of their comrade, or clearing up any of the dark fog of mystery that hung like a wet blanket between themselves and the solution.

Elmer immediately strode forward. By following the well-defined path he was able to find himself at what was plainly the rude door of the shack.

Upon this he knocked sharply. There came no answer, and even the keenest ears among the scouts failed to catch the slightest sound following this summons.

"Try it once more, Elmer," advised cautious Mark.

Again the tattoo sounded, but as before it produced no results. So Elmer opened the door, which he saw had been fashioned in the rudest way from boards, and hung upon strap hinges.

As he pushed the door aside, every scout held his breath and gripped his stick expectantly. But nothing happened. No string of rough men came bustling forth, demanding in coarse language what the boys meant by bothering them.

It looked as though Toby must have struck the right key when he so confidently declared there was nobody at home.

So Elmer entered, with some of the bolder among the scouts at his heels. The balance contented themselves in pressing around the door and window, and taking it out in looking.

Just as he had expected, Elmer found the interior of the shack pretty gloomy. Under the best of conditions very little daylight could find a way through such small openings, and these were now almost filled by the bodies of the curious scouts. But this was a matter easily remedied. Elmer had his matchsafe ready in his hands, and his first act was to strike a light.

As soon as the match flamed up he cast one quick look around the interior. This assured him that there were certainly no low-browed men crouching in the corners, and ready to hurl themselves upon the young invaders.

The next thing Elmer did was also a very natural move. He saw a candle in a bottle, standing on an upturned box, and stepping forward he applied his match to the waiting wick.

Then he looked around again.

There could be no doubt about this shack having been recently used as sleeping quarters by a number of men.

Several heaps of straw told where they lay, and Elmer counted four of these. Then there were a few bits of old clothing hanging from nails, a pair of heavy shoes, a frying pan, a kettle in which coffee might have been made, some broken bread, part of a ham, and some ears of corn; this last possibly stolen from the field of some farmer.

It looked like a tramp's paradise, but the puzzle was, what would tramps be doing so far away from all customary sources of supply?

Elmer sniffed the atmosphere, which was both heavy and far from pleasant. And Lil Artha, who had pressed into the shack, hot upon the heels of his chief, took note of his significant action.

"I should say yes, it's rank as all get out," he remarked, holding his nose between a finger and thumb. "Even beats that fishy smell we struck when we looked down into the cellar at the cottage. Whew!"

Others expressed themselves about as strongly, and little Jasper Merriweather, who had unwisely pushed into the shack, found it necessary to hurry out again, white of face and gasping.

But Elmer had conceived an idea, even while suffering from the unpleasant odor of the place.

"Howling cats!" exclaimed Lil Artha, "I don't see how you can stand it, Elmer. Talk to me about tramps, and the way they hate water, here's the rank evidence of it. Wow, ain't I sorry for poor Nat if he's got to associate with this hobo crowd for long!"

"But how do we know they're hoboes?" asked Elmer, turning on the tall scout.

"Hey? What's that?" exclaimed Lil Artha, actually so surprised that he neglected to hold that firm grip on his nose any longer.

"What makes you so sure they're tramps?" pursued the scout master.

"Why, goodness gracious alive, Elmer, you don't mean to say you doubt that now?" cried the tall boy, sweeping his hand around as though to draw attention to the various articles that seemed to stamp that theory a positive fact.

"Seeing these things here is what makes me question that idea very much," began Elmer; and then he picked up one of the old shoes, to hold it at arm's length. "Look at that, fellows; never made in this country, and you know it. Hobnails such as no one but foreigners use on their shoes."

"Well, I declare; I guess Elmer's right!" exclaimed Red.

"He certainly is, suh, take my word foh it," was the way Chatz expressed himself.

"Now look here, whoever saw a tramp's nest with anything like this in it?" and Elmer picked up a string of beads, evidently a rosary, that must have been overlooked in a hasty flight.

"Whew, that's going some!" ejaculated Phil Dale who, with his cousin Landy, happened to be in the shack eager to see all that went on.

"Perhaps he can even tell us what brand of foreigners these fellows are," remarked Landy, who was beginning to look upon Elmer pretty much in the light of a wizard.

"Oh, that ought to be easy, fellows," said the young scout master, as he reached up and took down a worn letter his quick eye had noticed stuck in a crack.

Every eye was immediately focused on the scout master. They knew his reasoning powers of old, and expected that Elmer would quickly put them on the right track now.

Indeed, hardly had the latter glanced at the well-worn letter he held than he smiled.

"What is it?" asked Red, impatiently.

"Yes, tell us what you've found out, Elmer," said Lil Artha.

"Why, look here at the name. As near as I can make out it's Giuseppi Caroni," replied the other.

"Wow, that is plain enough!" exclaimed Red.

"Sure Italiano," echoed the tall scout.

"Just as I thought," replied Elmer.

"But you can prove it," remarked Chatz.

"That's easy enough," added Dr. Ted, "the thtamp ought to be enough, you thee."

"And if it isn't, fellows, here's the postmark as plain as anything—Naples, Italy," continued Elmer.

"Naples, hey?" remarked Lil Artha. "Say, I was just reading about Naples the other day, and it said that next to the island of Sicily we get more of our Black Hand crowd from there than any other part of Garibaldi's old land."

A gasp seemed to go the complete rounds of all the khaki-clad warriors who thronged that mysterious little shack.

"Black Hand, you say, Lil Artha?" exclaimed Red.

"Yes, and anarchists, too; the kind that blow up the kings and queens of the Old World. The kind that abduct people so as to make their rich relatives whack up a big ransom."

"Oh!"

Some of the boys looked a little timid, and glanced around apprehensively, as though they anticipated seeing a whole bunch of fierce-looking dynamite users rise up around them.

Others shut their teeth together harder than ever, and these more determined fellows, it might be noticed, tightened the grip they had upon their sticks.

All eyes were turned again upon Elmer, who had listened to these remarks with an amused smile.

"Hold on your horses, boys," he said, raising his hand just then to still the rising dispute.

"Shut up, everybody; Elmer's got something more to tell us," Lil Artha cried.

The hubbub died away, and an eagerness to listen took its place; for every one of them was anxious to pick up points concerning the clever way their leader figured things out.

It was an important part of a scout's duty to learn how to read signs, not only when following a trail, but at all times.

And especially valuable would this qualification become when confronted by a baffling mystery such as the Hickory Ridge troop was now up against.

"Those who occupied this shack were four in number," Elmer began.

"How did you find that out?" asked Red.

"By the various tracks. So far as I could see there were just four separate kinds leading up to this place, and each one different."

"Hurrah! I tell you, fellows, that's the way to learn things. Elmer knows how to do it," cried Lil Artha.

Without even smiling at the implied compliment Elmer went on:

"Two of them wore shoes with hobnails just as you see on this old cast-off shoe here. A third one had on American-made brogans, and I expect they hurt him some, too, because he was limping as he walked. He is undoubtedly the chap who used to own these old foreign-made gun-boats."

"Hold on a minute, please, Elmer," pleaded Red.

"All right. You want to ask me something, and I think I know what it is," remarked the other.

"You say this fellow's new shoes hurt him, and made him limp; please tell us how in the wide world you ever found that out?" Red continued.

"Well, it might be possible that the fellow was always lame, but his tracks show plainly that he limped. Something was wrong with his left leg or foot, because the toe dug deeply into the ground."

"Well, I declare is that dead-sure evidence, Elmer?" demanded the astounded tenderfoot, Landy, who was listening with all his might to these intensely interesting facts as brought out by the scout master.

"Try it yourself sometime, Landy," remarked Elmer. "Pick out a nice piece of ground where the marks will show plainly. Limp as naturally as you can with the left leg. Then go back and examine the trail. You will find that not only does the left foot dig deeper at the toe than the right one, but that same toe drags a little over the ground as you bring the left foot forward each time."

"Just listen to that, will you!" remarked Red, "but I know Elmer is right. I can grab the principle of the thing."

"But how about the fourth one, Elmer; seems to me you've been holding back something there, that you mean to spring on us," said Lil Artha.

"Well, I have," remarked the other, quickly. "This fourth track was smaller than the others, and the person also wore American-made shoes."

"Ah, a boy, eh?" asked Red.

The scout master shook his head.

"Wrong that time, my boy. You'll have to guess again, I reckon," he said.

"Was it a woman, Elmer?" demanded Lil Artha.

"Just what it was—an Italian woman, squatty like most of her race; and I should say between fifty-five and sixty years of age," Elmer replied, soberly.