d around the cotton mills, the thread
mills, and the munition factories, were built many little homes of the
factory and mill hands. It had been pointed out by the local papers that
these homes were in double peril at this time.

Guards were on watch night and day that ill-affected persons should not
come into the district and blow up the munition factories. But there was
a second and greater danger to the people of Elmvale.

If anything should happen to the dam, if it should burst, the enormous
quantity of water held in leash by the structure would pour over the
village and cover half the houses to their chimney tops.

Two bridges crossed the river at Elmvale; one at the village proper and
the other just below the dam itself and about half a mile from the first
mill, Barron & Brothers' Thread Factory.

"Let's take the upper road," proposed Frenchy, as the car came within
sight of the chimneys of the Elmvale mills. "We've plenty of time before
the noon whistle blows. I haven't been up by the dam since before we all
joined the Navy."

"Just as you fellows say," Al responded, and turned into a side road
that soon brought them above the mills on the ridge overlooking the
valley.

"I say, fellows," Whistler stopped whistling long enough to observe,
"there's a slue of water behind that dam. S'pose she should let go all
of a sudden?"

"I'd rather be up here than down there," Al said.

"Oi, oi!" croaked Ikey, "you said something."

"I wonder if they guard that dam as they say they do the munition
factories," Frenchy put in.

Al turned the machine into the road that descended into the valley by a
sharp incline. In sight of the bridge which crossed the river Whistler
suddenly put his hand upon his chum's arm.

"Hold on, Torry," he said earnestly. "I bet that's one of the guards
now. See that fellow in the bushes over there?"

"I see the man you mean!" Frenchy exclaimed, leaning over the back of
the front seat of the automobile. "But he isn't in khaki. And he hasn't
got a gun."

All the Navy boys in the automobile, even Seven Knott, saw the man to
whom Whistler Morgan had first drawn attention. The man had his back to
the road. He was standing upright with a pair of field glasses to his
eyes. His interest seemed fixed on a point along the face of the dam
just where a thin slice of water ran over the flashboard into the rocky
bed of the river.

CHAPTER II

THE STRANGER

For the life of him Phil Morgan