majority of them were empty, but three, directed to one Jackson Dwight, Carwell, were full and nailed up.

"Well, I never!" murmured Sam. "Dick——"

"The freight thieves!" ejaculated the eldest Rover. "Don't you remember what was in the paper before we went south, and what was in again only yesterday? They have been missing freight from Carwell and Boxton and half a dozen other stations for over a year. The thieves must have brought their stuff here and then taken some of it from the packing cases and carted it away again."

"It certainly looks like it," answered Tom. "Only three full cases left. I wonder when these were taken?"

"Most likely only a short time ago," said Dick. "The cases look new."

"Do you suppose any of the freight thieves are around? If they are we want to keep out of their way—if they are desperate characters."

They moved on, and then Dick called a sudden halt.

"I can see daylight ahead," he said. "And somebody is moving around. Let us put out the torches."

His suggestion was speedily followed, and the three Rover boys advanced with caution. At its outer end the cave became broader while the roof was only about ten feet high.

"Hullo, here's another surprise," whispered Dick, as they came closer to the opening. "Look at that!"

He pointed to one side of the cave and there the others saw an automobile runabout standing and on the seat two men dressed for a tour. They were talking to a third man, who was lounging against a front wheel, smoking a brier-root pipe.

"Maybe they are the freight thieves," whispered Tom. "Let us get out of sight and listen to what they have to say."

It was an easy matter to keep out of sight, for the walls of the cave were very uneven at this point. They got behind a projection, and by crawling up a rocky ledge managed to reach a point above and to one side of the runabout and not over a dozen feet from it.

"Then you weren't going to stop here, Merrick?" asked the man leaning against the wheel.

"Not now, Dangler," was the reply of the man with the pipe. "The storm drove us in here."

"When do you expect to meet this Randolph Rover?"

"Very soon."

"He ought to be easy—he is so simple minded."

"Oh, I think we can work him right enough," put in the third man, who was tall and thin-cheeked.

"Well, if you do, don't forget that I get my share, Pike," said the man called Dangler.

"Haven't you always gotten your share?" demanded Pike.

"I suppose I have."

"And haven't we given you the information whenever any valuable freight was coming this way?" put in the man called Merrick.

"Yes, and got your full share of the proceeds, while I ran the risk," growled Dangler. "It's getting dangerous—I'm going to quit—after the next big haul," went on the man with the pipe.

"All right—as you wish," answered Merrick. "I wish this storm would let up. The road will be something fierce for our runabout."

"And bad for my wagon," growled Dangler in return.

The boys listened to the conversation with deep interest. The reference to their uncle amazed them, and they wondered what the two men in the runabout had in mind to do. By their talk it was evident they meant to accomplish something unlawful.

"They are going to play Uncle Randolph some trick," whispered Sam. "We must get home and warn him."

"What we ought to do is to have the whole crowd arrested," answered Tom. "They are all implicated in the theft of freight."

"That's the talk," said Dick. "The question is, How can we do it? We are no match for those three men, and more than likely they are armed."

After this the three men conversed in such a low tone the boys could not hear a quarter of what was said. But they learned enough to know that Merrick and Pike were going to meet their uncle and play him false in some way, and they heard the words "traction bonds" and "coupons" several times.

"Uncle Randolph had ten thousand dollars' worth of traction company bonds," said Dick. "He bought them only a short while ago. They pay five and a half per cent. interest and he thought them a first-class investment."

"Oh, we'll have to warn him," said Sam. "He is so open-hearted he would trust most anybody."

Merrick had descended from the runabout and gone out of the cave. Now he came back, said something to the others, and started up the auto. In another moment he had the machine turned around. Then it spun out of the cave and down a fairly good road in the direction of Carwell. The man named Dangler followed the runabout to the road and watched it disappear around a turn bordered by trees. The storm was now rolling away to the westward and the rain had ceased.

"They have gone!" cried Tom. "Where to?"

"Perhaps to our farm—to see Uncle Randolph," answered Sam. "We ought to follow them as quickly as we can."

"I think we had better capture the fellow left behind," said Dick. "We ought to be able to do it."

"That's the talk," said Tom. "Sure we can do it, being three to one."

Dangler watched the runabout and then gazed up and down the mountain for several minutes. Then of a sudden he started in a direction opposite to that taken by the machine.

"He is going away!" cried Sam.

"Come on after him!" called his big brother, and ran from the cave with the others at his heels. Just as he did this Dangler glanced back and saw them.

"Hey, you!" he cried in consternation.

"Stop!" called out Dick. "We want you."

At this command Dangler was more amazed than ever. But of a sudden he appeared to realize something of what had happened and commenced to run.

"Stop!" cried Tom and Sam, but at this the man only ran the faster.

"Come on—we've got to catch that rascal!" exclaimed Dick, and started to sprint. The others followed as quickly as they could, and a rapid chase along the mountain road ensued. But if the boys could run so could the freight robber, and he made the best possible use of his legs until he gained a side trail. Then he darted into this, and when the Rover boys came up he had disappeared.

"Where is he?" panted Sam.

"He took to this path, but he isn't in sight," answered Dick. He was almost winded himself.

"Come on, he must be somewhere around," put in Tom, and ran down the path several hundred feet. Then he tripped over a fallen log and went headlong in the bushes and wet grass. He got up looking tired out and cross.

"We've missed him," announced Dick, rather dismally. "It's a pity, too. He deserves to be put under arrest."

"I think we had better get home and warn Uncle Randolph," returned Sam. "If we don't there is no telling what that fellow Merrick and that Pike may do."

CHAPTER IV

AT THE FARM

The others considered Sam's advice good, and after another look around for Dangler, they turned in the direction of home. They were a good three miles from the farm and had to cross the river above the falls, thus adding half a mile more to the journey. It was wet and muddy walking and they had not covered over a mile when Tom called a halt.

"I am about fagged out," he announced. "Wonder if we can't hire a buggy at the next farmhouse."

"We can try anyway," answered Dick.

Directly after crossing the river they came to a small farmhouse, and walked around to the kitchen, where they saw an old woman shelling peas.

"We can't let you have any carriage," she said. "The men folks are to town and they've got the horses."

The boys were about to turn away when Dick thought of something.

"By the way, do you know a man named Dangler?" he asked.

"Sure, I do," was the answer.

"Does he live around here?"

"I guess he lives where he pleases. He is an old bachelor and comes and goes as he likes. He used to have a cottage down the pike, but it burnt down last winter."

"Then you haven't any idea