s us, I reckon."

"Maybe we can cut them off before they enter the cave," said Frank.
"They'll be busy about the airplane for several minutes before they
start to make their way to the cave. How would they have to approach
the cave?"

"Same way as us from the trees on," said Tom.

"Well, if we hurry," Frank declared excitedly, "maybe we can capture
them before they reach the cave."

"Right you are, young feller," approved Tom. "But we'll have to leave
our horses behind or they might give us away. We can't tie 'em to
those trees like we planned."

"We can't hobble them," said Jack, thinking quickly, "because they
would wander aside a little distance, anyway. And we may want them
again in a hurry."

"Tell you what," said Tom, "seems like I remember a clump o' trees
just this side o' them three I spoke about. We can tie 'em there. An'
them fellers in the machine won't have no horses, so ours ain't likely
to nicker."

"Good," said Jack. "You lead the way and we'll follow."

Presently at a low-spoken word from the guide the boys dismounted and
tied up their horses. Then, Jack carrying his rifle, and the others
following close at his heels, revolvers in hand, they pressed on
toward the three trees forming Tom Bodine's landmark.

As they reached the trees, low exclamations burst from the boys.
Hitherto, they had been cut off from the plateau by the shoulder of
the hill. Now it lay below and before them. This of itself would not
have permitted them to see, as the darkness was intense. But now the
scene was illuminated by a number of oil flares stuck upright in the
ground in a rude circle.

And right in the middle of the circle was the airplane stolen from Bob
and Frank. There could be no mistaking the all-metal body nor the
peculiar wing spread, even at that distance of close to half a mile.

Several figures were moving about. As the boys looked on, these seized
oil flares and started moving toward them.

"Here's where our turn comes at last," said Frank.

Jack laid a hand on his arm.

"Better than that, Frank," he said. "How many do you make out?"

"Three is my guess."

"The two men in the airplane and the man in charge of the cave," said
Jack. "Dollars to doughnuts, the cave is undefended right this minute.
What do you say to capturing it and laying for them there?"

All four were grouped together, and consequently all heard Jack's
proposal. Bob and Tom Bodine agreed eagerly.

"Lead the way, then, Tom,