etter keep an
eye open."

Trampled vegetation showed them the path to the firing place. Moving
cautiously, the boys walked down the path, eyes constantly searching for
signs of movement in the heavy growth.

The clearing where Connel had placed his shots was only a short distance
down the path. Rick examined it carefully, but it looked like all the
others, except for one thing. The broken earth was yellow, and of a
different texture than the deep jungle loam at the other stations.

Rick walked into the shattered area and picked up a piece of the yellow
ground. It broke in his hands. "Funny-looking stuff," he said.

"Yes," Scotty agreed. "Take a look around while I keep a watch. I have a
funny feeling we're not alone here."

There was a fairly deep crater in the middle of the area. Rick stepped
into it and kicked yellow earth out of his way. He was puzzled. There
was nothing visible in the area except the yellow ground, and there was
nothing about that to give him a clue to Connel's determination to keep
them away.

His foot dislodged a clump of earth. It rolled to the bottom of the
shot crater, exposing two large crystals. Rick picked them up and rubbed
the dirt off. They felt rather greasy. He didn't think they were quartz.
His mind ranged over the possibilities. Probably datolite, he decided.
The color was about right, and he knew datolite was found in igneous
rocks of volcanic origin. He put the crystals in his pocket.

A trace of blue caught his eye and he knelt, digging with his hands. He
uncovered a few more of the datolite crystals and put them in his
pocket. They weren't particularly good specimens; he had some in his
rock collection that were perfectly formed and clear, but at least they
were something to take home.

Digging uncovered a layer of hard blue rock, heavily pockmarked and
filled with the yellow ground. He saw one place where the blue actually
blended in with yellow and decided that the blue and yellow were
probably the same rock. The slaty blue simply turned to yellow when it
was exposed to the air for a while.

There were loose pieces of blue, broken by the dynamite blasts. He
picked up a couple of smaller pieces, then added a piece of yellow to
his collection. He uncovered another crystal, too, a large one nearly
the size of a golf ball and put that in his pocket.

Scotty was getting restless. "Let's get going," he said. "I don't like
this."

Rick had seen enough, and it had told him