From "Manual of Muad'Dib" by the Princess Irulan

the Universe" by Princess Irulan
The smuggler's spice factory with its parent carrier and ring of drone ornithopters came over a lifting of dunes like a swarm of insects following its queen. Ahead of the swarm lay one of the low rock ridges that lifted from the desert floor like small imitations of the Shield Wall. The dry beaches of the ridge were swept clean by a recent storm.
In the con-bubble of the factory, Gurney Halleck leaned forward, adjusted the oil lenses of his binoculars and examined the landscape. Beyond the ridge, he could see a dark patch that might be a spiceblow, and he gave the signal to a hovering ornithopter that sent it to investigate.
The 'thopter waggled its wings to indicate it had the signal. It broke away from the swarm, sped down toward the darkened sand, circled the area with its detectors dangling close to the surface.
Almost immediately, it went through the wing-tucked dip and circle that told the waiting factory that spice had been found.
Gurney sheathed his binoculars, knowing the others had seen the signal. He liked this spot. The ridge offered some shielding and protection. This was deep in the desert, an unlikely place for an ambush . . . still . . . Gurney signaled for a crew to hover over the ridge, to scan it, sent reserves to take up station in pattern around the area—not too high because then they could be seen from afar by Harkonnen detectors.
He doubted, though, that Harkonnen patrols would be this far south. This was still Fremen country.
Gurney checked his weapons, damning the fate that made shields useless out here. Anything that summoned a worm had to be avoided at all costs. He rubbed the inkvine scar along his jaw, studying the scene, decided it would be safest to lead a ground party through the ridge. Inspection on foot was still the most certain. You couldn't be too careful when Fremen and Harkonnen were at each other's throats.
It was Fremen that worried him here. They didn't mind trading for all the spice you could afford, but they were devils on the warpath if you stepped foot where they forbade you to go. And they were so devilishly cunning of late.
It annoyed Gurney, the cunning and adroitness in battle of these natives. They displayed a sophistication in warfare as good as anything he had ever encountered, and he had been trained by the best fighters in the universe then seasoned in battles where only the superior few survived.
Again Gurney scanned the landscape, wondering why he felt uneasy. Perhaps it was the worm they had seen . . . but that was on the other side of the ridge.
A head popped up into the con-bubble beside Gurney—the factory commander, a one-eyed old pirate with full beard, the blue eyes and milky teeth of a spice diet.
"Looks like a rich patch, sir," the factory commander said. "Shall I take 'er in?"
"Come down at the edge of that ridge," Gurney ordered. "Let me disembark with my men. You can tractor out to the spice from there. We'll have a look at that rock."
"Aye."
"In case of trouble," Gurney said, "save the factory. We'll lift in the 'thopters."
The factory commander saluted. "Aye, sir." He popped back down through the hatch.
Again Gurney scanned the horizon. He had to respect the possibility that there were Fremen here and he was trespassing. Fremen worried him, their toughness and unpredictability. Many things about this business worried him, but the rewards were great. The fact that he couldn't send spotters high overhead worried him, too. The necessity of radio silence added to his uneasiness.
The factory crawler turned, began to descend. Gently it glided down to the dry beach at the foot of the ridge. Treads touched sand.
Gurney opened the bubble dome, released his safety straps. The instant the factory stopped, he was out, slamming the bubble closed behind him, scrambling out over the tread guards to swing down to the sand beyond the emergency netting. The five men of his personal guard were out with him, emerging from the nose hatch. Others released the factory's carrier wing. It detached, lifted away to fly in a parking circle low overhead.
Immediately the big factory crawler lurched off, swinging away from the ridge toward the dark patch of spice out on the sand.
A 'thopter swooped down nearby, skidded to a stop. Another followed and another. They disgorged Gurney's platoon and lifted to hoverflight.
Gurney tested his muscles in his stillsuit, stretching. He left the filter mask off his face, losing moisture for the sake of a greater need—the carrying power of his voice if he had to shout commands. He began climbing up into the rocks, checking the terrain—pebbles and pea sand underfoot, the smell of spice.