Roscoe laughed inaudibly. "It's the same old Tommy
Slade. Well, I was just going to bean this geezer when my officer told
me I'd better follow him."

"I was following him, too," said Tom; "stalking is the word you ought to
use."

"Captain thought he might be up to something special. So I
followed--_stalked_--how's that?"

"All right."

"So I stalked him and when I saw he was following the stream I made a
detour and waited for him right here. You see what he was up to? Way
down in Cantigny they could turn a switch and start this blamed poison,
half a dozen hogsheads of it, flowing into the stream. They waited till
they lost the town before they turned the switch, and they probably
thought they could poison us Americans by wholesale. Maybe they had some
reason to think the blamed thing hadn't worked, and sent this fellow up.
I beaned him just as he was going to turn the stop-cock."

"Maybe you saved a whole lot of lives, hey?" said Tom proudly.

Roscoe shrugged his shoulder in that careless way he had. "I'll be glad
to meet any more that come along," he said.

It was well that Tom Slade's first sight of deliberate killing was in
connection with so despicable a proceeding as the wholesale poisoning of
a stream. He could feel no pity for the man who, fleeing from those who
fought cleanly and like men instead of beasts, had sought to pour this
potent liquid of anguish and death into the running crystal water. Such
acts, it seemed to him, were quite removed from the sphere of honorable,
manly fighting.

As a scout he had learned that it was wrong even to bathe in a stream
whence drinking water was obtained, and at camp he had always
scrupulously observed this good rule. He felt that it was cowardly to
defile the waters of a brook. It was not a "mailed fist" at all which
could do such things, but a fist dripping with poison.

And Tom Slade felt no qualm, as otherwise he might have felt, at hiding
there waiting for new victims. He was proud and thrilled to see his
friend, secreted in his perch, keen-eyed and alert, guarding alone the
crystal purity of this laughing, life-giving brook, as it hurried along
its pebbly bed and tumbled in little gushing falls and wound cheerily
around the rocks, bearing its grateful refreshment to the weary, thirsty
boys who were holding the neighboring village.

"I used to think I wouldn't like to be a sniper," he said, "but now it
seems different. I saw two fellers in the village and