That was true, Rick realized. "But why did he try to scare us off?" "It beats me. He wasn't a guard, I'm sure. If he was guarding something, he wouldn't have ridden off and left us there. And there wasn't anything personal in it, because he waved at me like an old pal. It was a kind of humorous wave. You know? Real jaunty." Rick asked the obvious question. "Was it the Earthman?" And Scotty made the obvious answer. "I didn't have a chance to ask him. Anyway, he didn't wear armor." Rick had been keeping his eye on 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.