of the line.

"You and Semi-Colon guard the wheel; and if anybody tries to escape that
way, I don't need to tell you what to do."

"And we'll do it, all right; won't we, Semi?" Corney boasted,
immediately swinging around, and heading toward the spot where the
moss-covered wheel of the deserted mill could be seen, with little
streams of water trickling over it from the broken sluiceway above.

"The rest of us will tackle one of the doors, and break it in, if it's
fast," Fred went on to say.

"And don't let's be all day about it, either," remarked the impatient
Bristles, who was fretting all the while because he could not be doing
something.

"Come on!" said Fred.

He headed straight for the nearest door as he spoke, with three anxious
followers at his heels. Felix Wagner was looking particularly well
pleased. He had not anticipated such a treat when deciding to walk all
the way back from Tenafly that morning. And he felt that things were all
coming in his direction at a furious rate.

"Fast; eh, Fred?" asked Sid, as he saw the other make a vain attempt to
open the door of the mill; through which doubtless the office had been
reached in times past, when the neighboring farmers all came here daily
to have their grist ground, and to carry home their flour.

"It sure is; I can't seem to budge it," came the reply.

"Wonder if they went in here?" hazarded Bristles, himself giving a
fierce though ineffective push.

"We can settle that easy enough," remarked Fred; "by seeing if there are
any signs of new footprints here before this door."

"Well, you do take the cake thinkin' up things," muttered Bristles, as
he dropped down to examine the soil.

"They're here, all right, Fred!" he announced quickly, in a thrilling
whisper.

"Perhaps you even see that shoe print that shows the patch?" asked Fred.

"Right you are," Bristles immediately announced; "just what you told us
to watch for. Boys, we've tracked the abductors of our chum to their
lair; and now to smash in the door, and jump 'em!"

"But however in the wide world do you think they got in here, if the old
door is locked?" demanded Wagner, curiously, and wondering if Fred could
give an answer to that question as easily as he seemed to solve other
mysteries.

"I think a key has been used here lately," replied the other. "I can see
marks around the keyhole to tell that. Chances are, they had one made to
fit the door. A smart fellow could take an impression of