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

Parting with people is a sadness; a place is only a place ."
"They're using Sardaukar," Jessica said. "We must wait until the Sardaukar have been withdrawn."
"They think us caught between the desert and the Sardaukar," Paul said. "They intend that there be no Atreides survivors—total extermination. Do not count on any of our people escaping."
"They cannot go on indefinitely risking exposure of the Emperor's part in this."
"Can't they?"
"Some of our people are bound to escape."
"Are they?"
Jessica turned away, frightened of the bitter strength in her son's voice, hearing the precise assessment of chances. She sensed that his mind had leaped ahead of her, that it now saw more in some respects than she did. She had helped train the intelligence which did this, but now she found herself fearful of it. Her thoughts turned, seeking toward the lost sanctuary of her Duke, and tears burned her eyes.
This is the way it had to be, Leto , she thought. "A time of love and a time of grief ." She rested her hand on her abdomen, awareness focused on the embryo there. I have the Atreides daughter I was ordered to produce, but the Reverend Mother was wrong: a daughter wouldn't have saved my Leto. This child is only life reaching for the future in the midst of death. I conceived out of instinct and not out of obedience .
"Try the communinet receiver again," Paul said.
The mind goes on working no matter how we try to hold it back , she thought.
Jessica found the tiny receiver Idaho had left for them, flipped its switch. A green light glowed on the instrument's face. Tinny screeching came from its speaker. She reduced the volume, hunted across the bands. A voice speaking Atreides battle language came into the tent.
" . . . back and regroup at the ridge. Fedor reports no survivors in Carthag and the Guild Bank has been sacked."
Carthag! Jessica thought. That was a Harkonnen hotbed .
"They're Sardaukar," the voice said. "Watch out for Sardaukar in Atreides uniforms. They're—"
A roaring filled the speaker, then silence.
"Try the other bands," Paul said.
"Do you realize what that means?" Jessica asked.
"I expected it. They want the Guild to blame us for destruction of their bank. With the Guild against us, we're trapped on Arrakis. Try the other bands."
She weighed his words: I expected it . What had happened to him? Slowly, Jessica returned to the instrument. As she moved the bandslide, they caught glimpses of violence in the few voices calling out in Atreides battle language: ". . . fallback . . ." ". . . try to regroup at . . ." ". . . trapped in a cave at. . . ."
And there was no mistaking the victorious exultation in the Harkonnen gibberish that poured from the other bands. Sharp commands, battle reports. There wasn't enough of it for Jessica to register and break the language, but the tone was obvious.
Harkonnen victory.
Paul shook the pack beside him, hearing the two literjons of water gurgle there. He took a deep breath, looked up through the transparent end of the tent at the rock escarpment outlined against the stars. His left hand felt the sphincter-seal of the tent's entrance. "It'll be dawn soon," he said. "We can wait through the day for Idaho , but not through another night. In the desert, you must travel by night and rest in shade through the day."
Remembered lore insinuated itself into Jessica's mind: Without a stillsuit, a man sitting in shade on the desert needs five liters of water a day to maintain body weight . She felt the slick-soft skin of the stillsuit against her body, thinking how their lives depended on these garments.
"If we leave here, Idaho can't find us," she said.
"There are ways to make any man talk," he said. "If Idaho hasn't returned by dawn, we must consider the possibility he has been captured. How long do you think he could hold out?"
The question required no answer, and she sat in silence.
Paul lifted the seal on the pack, pulled out a tiny micromanual with glowtab and magnifier. Green and orange letters leaped up at him from the pages: "literjons, stilltent, energy caps, recaths, sandsnork, binoculars, stillsuit repkit, baradye pistol, sinkchart, filt-plugs, paracompass, maker hooks, thumpers, Fremkit, fire pillar . . . "
So many things for survival on the desert.
Presently, he put the manual aside on the tent floor.
"Where can we possibly go?" Jessica asked.
"My father spoke of desert power ," Paul said. "The Harkonnens cannot rule this planet without it. They've never ruled this planet, nor shall they. Not even with ten thousand legions of Sardaukar."
"Paul, you can't think that—"
"We've all the evidence in our hands," he said. "Right here in this tent—the tent itself, this pack and its contents, these stillsuits. We know the Guild wants a prohibitive price for weather satellites. We know that—"
"What've weather satellites to do with it?" she asked. "They couldn't possibly . . . " She broke off.
Paul sensed the hyperalertness of his mind reading her reactions, computing on minutiae. "You see it now," he said. "Satellites watch the terrain below. There are things in the deep desert that will not bear frequent inspection."
"You're suggesting the Guild itself controls this planet?"
She was so slow.
"No!" he said. "The Fremen! They're paying the Guild for privacy, paying in a coin that's freely available to anyone with desert power—spice. This is more than a second-approximation answer; it's the straight-line computation. Depend on it."
"Paul." Jessica said, "you're not a Mentat yet; you can't know for sure how—"
"I'll never be a Mentat," he said. "I'm something else . . . a freak."
"Paul! How can you say such—"
"Leave me alone!"
He turned away from her, looking out into the night. Why can't I mourn? he wondered. He felt that every fiber of his being craved this release, but it would be denied him forever.
Jessica had never heard such distress in her son's voice. She wanted to reach out to him, hold him, comfort him, help him—but she sensed there was nothing she could do. He had to solve this problem by himself.
The glowing tab of the Fremkit manual between them on the tent floor caught her eye. She lifted it, glanced at the flyleaf, reading: "Manual of 'The Friendly Desert,' the place full of life. Here are the ayat and burhan of Life. Believe, and al-Lat shall never burn you."