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

How can he think of attack at a time like this? she asked herself.
"An entire planet full of spice," she said. "How can you hit them there?"
She heard him stirring, the sound of their pack being dragged across the tent floor.
"It was sea power and air power on Caladan," he said. "Here, it's desert power . The Fremen are the key."
His voice came from the vicinity of the tent's sphincter. Her Bene Gesserit training sensed in his tone an unresolved bitterness toward her.
All his life he has been trained to hate Harkonnens , she thought. Now, he finds he is Harkonnen . . . because of me. How little he knows me! I was my Duke's only woman. I accepted his life and his values even to defying my Bene Gesserit orders .
The tent's glowtab came alight under Paul's hand, filled the domed area with green radiance. Paul crouched at the sphincter, his stillsuit hood adjusted for the open desert—forehead capped, mouth filter in place, nose plugs adjusted. Only his dark eyes were visible: a narrow band of face that turned once toward her and away.
"Secure yourself for the open," he said, and his voice was blurred behind the filter.
Jessica pulled the filter across her mouth, began adjusting her hood as she watched Paul break the tent seal.
Sand rasped as he opened the sphincter and a burred fizzle of grains ran into the tent before he could immobilize it with a static compaction tool. A hole grew in the sandwall as the tool realigned the grains. He slipped out and her ears followed his progress to the surface.
What will we find out there? she wondered. Harkonnen troops and the Sardaukar, those are dangers we can expect. But what of the dangers we don't know?
She thought of the compaction tool and the other strange instruments in the pack. Each of these tools suddenly stood in her mind as a sign of mysterious dangers.
She felt then a hot breeze from surface sand touch her cheeks where they were exposed above the filter.
"Pass up the pack." It was Paul's voice, low and guarded.
She moved to obey, heard the water literjons gurgle as she shoved the pack across the floor. She peered upward, saw Paul framed against stars.
"Here," he said and reached down, pulled the pack to the surface.
Now she saw only the circle of stars. They were like the luminous tips of weapons aimed down at her. A shower of meteors crossed her patch of night. The meteors seemed to her like a warning, like tiger stripes, like luminous grave slats clabbering her blood. And she felt the chill of the price on their heads.
"Hurry up," Paul said. "I want to collapse the tent."
A shower of sand from the surface brushed her left hand. How much sand will the hand hold? She asked herself.
"Shall I help you?" Paul asked.
"No."
She swallowed in a dry throat, slipped into the hole, felt static-packed sand rasp under her hands. Paul reached down, took her arm. She stood beside him on a smooth patch of starlit desert, stared around. Sand almost brimmed their basin, leaving only a dim lip of surrounding rock. She probed the farther darkness with her trained senses.
Noise of small animals.
Birds.
A fall of dislodged sand and faint creature sounds within it.
Paul collapsing their tent, recovering it up the hole.
Starlight displaced just enough of the night to charge each shadow with menace. She looked at patches of blackness.
Black is a blind remembering , she thought. You listen for pack sounds, for the cries of those who hunted your ancestors in a past so ancient only your most primitive cells remember. The ears see. The nostrils see .
Presently, Paul stood beside her, said: " Duncan told me that if he was captured, he could hold out . . . this long. We must leave here now." He shouldered the pack, crossed to the shallow lip of the basin, climbed to a ledge that looked down on open desert.
Jessica followed automatically, noting how she now lived in her son's orbit.