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."

Scarcely daring to breathe, now that they knew the strange men were so
close, the three Rover boys walked to the open doorway of the old mill
and went inside. Dick led the way and crossed to where an enclosed
stairs ran to the floor below. On tiptoes he went down, not trusting a
step until he was sure of his footing. It was well he did this, for two
of the steps were entirely rotted away, and he had to warn his
brothers, otherwise one or another might have had a fall.

Standing in the wheel room of the old mill the boys saw another streak
of light, coming from the room which Dick had suggeste