short
whistle. If all is well you will reply with two short whistles."

"You are going back there to spy on that outfit that we just left?"
questioned Hippy.

"Yes. I want to see who the others are, and what they have up their
sleeves. Here's a revolver for you. I suppose they took yours. Don't use
it unless you have to."

"Wait a moment!" called Hippy, as his mysterious friend started away.
"Haven't you forgotten something? That 'snack' you promised to dig
for."

"Oh, yes. Here's some dog biscuit for you, and--"

"Dog biscuit?" exclaimed Hippy.

"Hardtack. You ought to know what that is," chuckled the stranger.

Hippy groaned. It revived painful memories of France in wartime, but he
accepted the hardtack and began biting it off in large chunks. Hippy did
not concern himself about how long the mysterious friend remained away
so long as the biscuit held out, unpalatable as it was.

"I shall be listening for shells to burst first thing I know. Army food!
How did I ever eat it for nearly two years and live?"

It was full two hours later when the welcome whistle signal sounded
somewhere down stream, which Lieutenant Wingate answered as directed.

"Come! We will head for your camp now," announced the man a few moments
later, as he stepped up before Hippy.

"Did you learn anything on your little excursion?" questioned Hippy
thickly, for his mouth was well filled with hardtack.

"Yes, Lieutenant. I learned a great deal. I was there when the crowd
came in to put you on the rack. The two fellows who let you get away
had a hard time of it, and it looked for a time as if there was going to
be shooting. Cooler heads, however, headed it off. When you get back to
your party I should advise you to pull up stakes and get out. Those
fellows will be after you and you'll have to look alive or you won't be
alive long."

"I know I am thick, old man, but tell me why they are so eager to blow
my light out," begged Hippy.

"Don't you know, Lieutenant?"

"If I did I shouldn't be asking you. Begging your pardon for my
bluntness."

"One reason, but not the principal one, is that you bounced one of the
gang from your camp."

"Go on. What's the big idea?"

"The big idea, as you call it, is that there is a price on your head up
here! Now do you understand, Lieutenant?"

Hippy Wingate uttered a low, long-drawn whistle of amazement.

CHAPTER IX

THE POWER OF MIND

"What do you suppose it can mean, and who threw it