the road ahead. "Pull over," he said
quickly. "Let's get out and be looking at cactus or something. I think
Mac and Pancho are coming."

Scotty complied quickly and shut off the jeep engine. The boys got out
and walked quickly into the desert, found a barrel cactus, and began
dissecting it with Rick's scout knife.

The dust cloud that marked an oncoming vehicle grew larger, and in a few
minutes they saw the panel truck and the trailer with radar dish mounted
on it. As the truck drew nearer they stood up, Rick holding the cactus
impaled on his knife. It was a natural action; simple curiosity would
require that they pause to see who might be in a passing vehicle.

The truck drew abreast and slowed. Big Mac was driving. Pancho leaned
out and waved. "Hiya, kids!"

They echoed him. "Hiya, Pancho." Then the truck was past, en route to
the mesa for the day's dry run.

Rick drew a deep breath. "In the clear," he said with relief. Suddenly
he grinned. "This is what I call progress. We go to Careless Mesa. We
find nothing. We get shot at. We add to the mystery without adding a
single thing to the puzzle. One more day like this and we'll have to put
our Junior G-man badges back in the cereal box where we got 'em."

"I beat you," Scotty said unhappily. "I left mine under a rock at the
top of the mesa."

CHAPTER VIII

Project Orion

There was an air of anticipation everywhere at the Scarlet Lake rocket
base. Rick, who was sensitive to such things, felt it keenly. He also
recognized that under the anticipation, like thick, stagnant water under
the bright surface of a pond, there was fear.

The anticipation was spoken; the fear was not.

By mutual agreement, Rick and Scotty parted soon after their return to
the base. Each went back to his own unit, more on guard then ever before
for the slightest hint of irregularity in personnel or equipment.

The electronics group of Pegasus was just about at a standstill. Dick
Earle and Frank Miller had gone to the firing area, to lend the Orion
group a hand. Dr. Bond remained, along with Kassick and Sherman. The
three were amusing themselves with a game of three-handed bridge, while
the marmoset occasionally made things lively by stealing cards.

Rick watched for a few minutes, then wandered into the empty Orion shed,
abandoned now that its crew and rocket had moved to the firing pad and
blockhouse. As he stood looking at the complex test equipment a sedan
pulled up and Ge