ooking for a lost son. It was supposed that
this Nate Duncan was Joe's father.

As nothing toward finding Mr. Duncan could then be done, Joe and Blake
kept on toward the Indian country. A cowboy, Hank Selby, offered to
accompany them, and they were glad he did.

They had many adventures before getting on the track of the Indians, and
when they found them in a secret valley, and, concealed in a cave, began
taking moving pictures, they discovered, as I have said, four white men
in danger of torture.

How they rescued them, how the troopers came, and how one turned out to
be Bill Duncan, Joe's half-uncle, I have mentioned in this book as well
as in the second volume. And, on their way back to Big B ranch and to
Flagstaff, the night attack had taken place.

"How are you making out, Blake?" asked Joe, as he worked at stacking up
the boxes and bales into a sort of rude breastwork near the shelter
tents.

"All right, Joe," was the answer. "I hope Hank makes the animals safe."

"He doesn't seem to be having much trouble. I can't see any of the
Indians now."

"No, they're probably hiding down in the grass, waiting for a chance to
make a raid. I wonder how many there are?"

"Quite a bunch, I should say, from the shooting. Here comes Hank now."

As he spoke, the cowboy appeared, leading by their long tether ropes the
riding ponies and the pack animals. The steeds showed signs of their
recent excitement. Had it not been for the alarm they gave they might
have been stolen without our friends being any the wiser.

"See any of 'em, Hank?" questioned Joe.

"No, but they're there, all right. Boys, there may be some hot work
ahead of us. You want to get ready for it."

"Do--do you think they'll shoot?" asked Blake.

"Well, they'll do their best to get our things away from us," was the
answer. "They're desperate, I'm afraid."

Hank busied himself tethering the steeds nearer the temporary camp,
while Joe and Blake finished their labors in building a defense against
the possible rush of the redmen.

This was hardly finished, and they had scarcely collected a pile of
brush to make a bright fire, if necessary, when there arose all around
fierce shouts. At the same time there was a fusillade of shots; but, as
far as could be seen, all the Indians were firing in the air.

"Look out!" yelled Hank. "They're going to rush us!"

Before he ceased speaking there was the sound of many feet running
forward. The shooting and shoutin