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

Plans within plans within plans within plans , Jessica thought. Have we become part of someone else's plan now?
The arrows led them around turnings, past side openings only dimly sensed in the faint luminescence. Their way slanted downward for a time, then up, ever up. They came finally to steps, rounded a corner and were brought short by a glowing wall with a dark handle visible in its center.
Paul pressed the handle.
The wall swung away from them. Light flared to reveal a rock-hewn cavern with an ornithopter squatting in its center. A flat gray wall with a doorsign on it loomed beyond the aircraft.
"Where did Kynes go?" Jessica asked.
"He did what any good guerrilla leader would," Paul said. "He separated us into two parties and arranged that he couldn't reveal where we are if he's captured. He won't really know."
Paul drew her into the room, noting how their feet kicked up dust on the floor.
"No one's been here for a long time," he said.
"He seemed confident the Fremen could find us," she said.
"I share that confidence."
Paul released her hand, crossed to the ornithopter's left door, opened it, and secured his pack in the rear. "This ship's proximity masked," he said. "Instrument panel has remote door control, light control. Eighty years under the Harkonnens taught them to be thorough."
Jessica leaned against the craft's other side, catching her breath.
"The Harkonnens will have a covering force over this area," she said. "They're not stupid." She considered her direction sense, pointed right. "The storm we saw is that way."
Paul nodded, fighting an abrupt reluctance to move. He knew its cause, but found no help in the knowledge. Somewhere this night he had passed a decision-nexus into the deep unknown. He knew the time-area surrounding them, but the here-and-now existed as a place of mystery. It was as though he had seen himself from a distance go out of sight down into a valley. Of the countless paths up out of that valley, some might carry a Paul Atreides back into sight, but many would not.
"The longer we wait the better prepared they'll be," Jessica said.
"Get in and strap yourself down," he said.
He joined her in the ornithopter, still wrestling with the thought that this was blind ground, unseen in any prescient vision. And he realized with an abrupt sense of shock that he had been giving more and more reliance to prescient memory and it had weakened him for this particular emergency.
"If you rely only on your eyes, your other senses weaken." It was a Bene Gesserit axiom. He took it to himself now, promising never again to fall into that trap . . . if he lived through this.
Paul fastened his safety harness, saw that his mother was secure, checked the aircraft. The wings were at full spread-rest, their delicate metal interleavings extended. He touched the retractor bar, watched the wings shorten for jet-boost take-off the way Gurney Halleck had taught him. The starter switch moved easily. Dials on the instrument panel came alive as the jetpods were armed. Turbines began their low hissing.
"Ready?" he asked.
"Yes."
He touched the remote control for lights.
Darkness blanketed them.
His hand was a shadow against the luminous dials as he tripped the remote door control. Grating sounded ahead of them. A cascade of sand swished away to silence. A dusty breeze touched Paul's cheeks. He closed his door, feeling the sudden pressure.
A wide patch of dust-blurred stars framed in angular darkness appeared where the door-wall had been. Starlight defined a shelf beyond, a suggestion of sand ripples.
Paul depressed the glowing action-sequence switch on his panel. The wings snapped back and down, hurling the 'thopter out of its nest. Power surged from the jetpods as the wings locked into lift attitude.
Jessica let her hands ride lightly on the dual controls, feeling the sureness of her son's movements. She was frightened, yet exhilarated. Now, Paul's training is our only hope , she thought. His youth and swiftness .
Paul fed more power to the jetpods. The 'thopter banked, sinking them into their seats as a dark wall lifted against the stars ahead. He gave the craft more wing, more power. Another burst of lifting wingbeats and they came out over rocks, silver-frosted angles and outcroppings in the starlight. The dust-reddened second moon showed itself above the horizon to their right, defining the ribbon trail of the storm.
Paul's hands danced over the controls. Wings snicked in to beetle stubs. G-force pulled at their flesh as the craft came around in a tight bank.
"Jetflares behind us!" Jessica said.
"I saw them."
He slammed the power arm forward.
Their 'thopter leaped like a frightened animal, surged southwest toward the storm and the great curve of desert. In the near distance, Paul saw scattered shadows telling where the line of rocks ended, the basement complex sinking beneath the dunes. Beyond stretched moonlit fingernail shadows—dunes diminishing one into another.
And above the horizon climbed the flat immensity of the storm like a wall against the stars.
Something jarred the 'thopter.
"Shellburst!" Jessica gasped. "They're using some kind of projectile weapon."
She saw a sudden animal grin on Paul's face. "They seem to be avoiding their lasguns," he said.
"But we've no shields!"
"Do they know that?"
Again the 'thopter shuddered.
Paul twisted to peer back. "Only one of them appears to be fast enough to keep up with us."
He returned his attention to their course, watching the storm wall grow high in front of them. It loomed like a tangible solid.
"Projectile launchers, rockets, all the ancient weaponry—that's one thing we'll give the Fremen," Paul whispered.
"The storm," Jessica said. "Hadn't you better turn?"
"What about the ship behind us?"
"He's pulling up."
"Now!"
Paul stubbed the wings, banked hard left into the deceptively slow boiling of the storm wall, felt his cheeks pull in the G-force.
They appeared to glide into a slow clouding of dust that grew heavier and heavier until it blotted out the desert and the moon. The aircraft became a long, horizontal whisper of darkness lighted only by the green luminosity of the instrument panel.
Through Jessica's mind flashed all the warnings about such storms—that they cut metal like butter, etched flesh to bone and ate away the bones. She felt the buffeting of dust-blanketed wind. It twisted them as Paul fought the controls. She saw him chop the power, felt the ship buck. The metal around them hissed and trembled.
"Sand!" Jessica shouted.
She saw the negative shake of his head in the light from the panel. "Not much sand this high."
But she could feel them sinking deeper into the maelstrom.
Paul sent the wings to their full soaring length, heard them creak with the strain. He kept his eyes fixed on the instruments, gliding by instinct, fighting for altitude.
The sound of their passage diminished.
The 'thopter began rolling off to the left. Paul focused on the glowing globe within the attitude curve, fought his craft back to level flight.
Jessica had the eerie feeling that they were standing still, that all motion was external. A vague tan flowing against the windows, a rumbling hiss reminded her of the powers around them.