"Some one's getting in on this," they heard one of the voices say, as though its owner were nervous, yet was trying his best to hide his uneasiness. "Let's take a look around, boys. You never can be too sure."

The radio boys looked at each other in consternation. There was no time to get away, even if they had wanted to. And now that they were convinced there was crooked work going on in the shack, they certainly did not want to leave.

Bob flattened himself against the wall and motioned to his chums to do likewise. If the fellows found them and wanted to put up a fight, "well, they'd get their money's worth, anyway."

But it so happened that the lads were not discovered. The door of the shack was on the opposite side from them, and either the men were too lazy to search carefully or they were too confident of the obscurity of their meeting place. At any rate, they went to the door, looked around, and, finding no one within sight, evidently decided that they had been mistaken in thinking they had heard a suspicious noise and reentered the shack without searching further.

"You're crazy, Mohun," the boys heard one of them remark, in an irritable voice. "You're letting your imagination--and your nerves--run away with you."

"Well, this deal is enough to get on anybody's nerves," was the grumbled reply, evidently from the person addressed as Mohun. "If we don't put it across pretty quick I'm going to quit. I've told you too much delay would be fatal."

The boys glanced at each other, and the relief they had felt at not being discovered was closely followed by huge excitement as they became more and more certain that they were on the verge of making an important discovery.

They crowded closer to the window though, mindful of how close they had come to discovery, they were careful to make not the slightest sound.

Bob, who was closest to the window, could, by exercising the greatest caution, peer into the shadows of the room. He put out his hand as a warning to Joe, who was crowding him closely.

"Don't push," he said, in the merest whisper. "I have a notion this is going to be good."

So had the other boys, but they were mad clean through at the fate that prevented their getting a glimpse into the tumbled-down shanty.

However, they held back, knowing that if they were too eager they would spoil everything. Discovery then would mean that they would never hear the secret these men were about to disclose.

The old shack had evidently once been lived in, for it was fitted up with furniture of a crude sort. Along one side of the room ran two long bunks, one above the other, and on the walls were some old dilapidated-looking pictures, evidently cut out of magazines or news periodicals.

There was a three-legged, rickety table in the center of the room, and about this the conspirators--for such they were--were gathered. Two of the men had chairs, patently home-made, for seats, while the third, who sat facing Bob, had merely an empty wooden box turned on end.

It was this last fellow who was now speaking and who had been addressed by the name of Mohun. He was short and of fair complexion, with protruding, horsey teeth that stuck out disagreeably over his lip.

Another of the trio was a giant of a fellow, tall, dark and heavy-browed, while the third, who sat with his back to Bob, was of slighter build, but nearly as tall.

Mohun seemed to be the leader of the party, for now he was leaning across the rickety table, talking earnestly and emphasizing his remarks with blows of his fist upon it.

"I tell you, Merriweather," he said, addressing the giant, "this is our time to act. You are merely p.u.s.s.y-footing when you ask delay. I am convinced that delay means suicide."

Jimmy, catching the last word, gasped involuntarily and Bob nudged him warningly.

"Keep still," he hissed. "This sure is going to be good!"

The two other men looked uncertain but the fellow called Mohun was pushing the point home.

"This is our chance," he cried vehemently. "Salper is out of the way for the present, but we never know when he may take the notion to go back to the old job. They say he is getting mighty restive already."

At the mention of Mr. Salper's name Bob fell back in his amazement and landed on Joe's foot, whereupon the latter emitted a squeak of pain that he immediately stifled.

"Did you hear that?" demanded Bob in an excited whisper, without a thought for poor Joe's foot. "They're talking about Mr. Salper."

Eagerly he turned back to the window while Herb whispered in an awed tone:

"Maybe they're going to murder the old fellow."

"Say, keep still, can't you?" said Bob impatiently, as he strained his ears to catch the lowered tones of the three men.

Herb subsided, and the four of them waited with bated breath to find out what these three conspirators had to do with Gilbert Salper.

"Maybe you're right, Mohun," the tall man with the craggy brows answered reluctantly. "But I can't help thinking that to strike now is a poor move."

"In two or three weeks we'll have everything just as we want it,"

added the man who sat with his back to Bob. "We'll have a sure thing then, while now----"

The man called Mohun threw up his hands in a gesture of despair.

"p.u.s.s.y-footing again!" he cried disgustedly. "What kind of gamblers are you, anyway, to wait until you have a sure thing before you test your luck? Don't you know that the big deals down on the Street that have been successful have been put through because the fellows doing it had nerve?"

"Yes, but not many of the deals have been as big or as important as this," said the giant quietly.

"All the more reason to strike quickly," argued Mohun, with heat, adding in a lowered tone: "I tell you this absence of Salper from Wall Street is the chance of a lifetime. It's the thing we've been waiting for. With him on the Street we haven't a chance for our lives. With him away, we have everything in our own hands. Now it's up to you whether we make the most of our luck, or throw it in the rubbish heap."

"But Salper is up here for an indefinite length of time," argued the man with his back to Bob. "It is said he will stay at least a month, maybe two. And a week--two at the outside--is all we need to make sure of relieving him of some of his ill-gotten wealth."

The man laughed noisily at this poor attempt at humor, and Mohun glanced nervously about him.

"Better look out," he said, peevishly. "You never can tell who's listening. They say the trees have ears around this way."

"Your nerves are getting the best of you, I think," cried the big man.

"Just because you've got cold feet is no reason why we should take the chance of losing out on the biggest deal we've had the chance of handling for many a day. Get a good sleep, man, and you'll think the way we do, tomorrow."

For a moment it seemed as though Mohun were about to spring upon the big man and Bob held his breath, expecting a struggle. Mohun's face turned a brick red and his lips drew back from his protruding upper teeth as though in a snarl. His hands clenched, he took a step toward the bigger man who had half risen from his chair.

"Then I'll tell you one thing, you p.u.s.s.y-footers!" he cried furiously.

"If this deal isn't pulled through by the end of a week and if by that time we haven't our hands on a good chunk of Salper's money, then I'm through. Do you hear that? I quit!"

CHAPTER XIX

ON GUARD

The radio boys had heard enough. Silently they tiptoed from their vantage point, putting off the tremendous desire to exclaim about what they had heard until they had put a good distance between themselves and the shack.

Then they overflowed with wonder and excitement.

"Say, wait till we spring this news on Mr. Salper!" cried Herb. "The man will near go off his head."

"Gosh, you couldn't blame him," said Joe, in an awed tone. "I wouldn't like to have those three fellows after my hard-earned cash myself."

"Then he was right when he thought there was somebody after his money," said Bob, striding along so swiftly in his excitement that poor Jimmy had hard work to keep up with him. "We thought he was kind of crazy, but I guess he knew what he was talking about all the time."