It was no easy matter to climb around or over the rocks which lay between the boys and the old mill, and the darkness under the thick trees was intense.  They felt their way along slowly, and Tom was careful to carry the shotgun with the barrel pointed downward, that there might be no accident.

“More than likely those fellows have been putting up at the old mill,” said Dick.

“They’ll leave now—­if they think we are coming,” answered Sam.

“Let us keep quiet,” put in Tom.  “If they hear us talking they will surely skip out.”

After that but little was said.  Foot by foot they drew closer to the dilapidated structure, until it loomed up dimly before them.  Then Dick motioned for the others to halt.

With bated breath the boys listened.  At first they heard little but the rushing of the water over the rocks.  Then came a sudden cracking of a rotten floor board, followed by an exclamation.

“Confound the luck!  I’ve put my foot through the floor again,” growled a man’s voice.  “Shelley, why don’t you light the lantern?  Do you want me to break my neck?”

“If I light the lantern the Rovers may come here,” was the answer from the man called Shelley.

“Oh, they went down the river I saw them.”

“They may have turned in nearby.”

Some more words followed, but spoken so low that the boys could not understand them.  They heard a faint creaking of the flooring of the old mill, but that was all.

“They are there, that’s certain,” whispered Dick.  “But I don’t see how we are going to capture them in this darkness.”

“I wish we had a lantern,” said the youngest Rover.

“We wouldn’t dare to light it, Sam,” answered Tom.  “Let us crawl up close to the building.  Maybe we can find out something more about the men.  They may be some good for nothing fellows from the village.”

As there seemed nothing else to do, this advice was followed, and soon the boys were at one of the broken out windows of the mill.  They listened and looked inside, but saw and heard nothing.

“They are not here,” whispered Sam, disappointedly.

“They are not far off,” answered his big brother confidently.

“Look!” came from Tom.  “A light!”

He pointed through the window to the flooring inside.  From between the loose boards shone several streaks of light.  As the boys gazed the light vanished and all was as dark as before.

“They are in the lower room, the one where the water wheel used to be,” whispered Tom.  “Maybe that is where they have been hanging out.”

“Come after me—­but don’t make any noise,” said Dick, cautiously.  “If they have gone into the second room down there maybe we can make them prisoners!”

“That’s the idea!” cried Sam.  “Just the thing!”

“Hush, Sam, or you’ll spoil all.”