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

Why did he summon me? she asked herself. He told me before that I must remain in the south with little Leto and Alia .
She gathered her robe and leaped lightly up across a barrier rock and onto the climbing path that only the desert-trained could recognize in the darkness. Pebbles slithered underfoot and she danced across them without considering the nimbleness required.
The climb was exhilarating, easing the fears that had fermented in her because of her escort's silent withdrawal and the fact that a precious 'thopter had been sent for her. She felt the inner leaping at the nearness of reunion with Paul-Muad'Dib, her Usul. His name might be a battle cry over all the land: "Muad'Dib! Muad'Dib! Muad'Dib! " But she knew a different man by a different name—the father of her son, the tender lover.
A great figure loomed out of the rocks above her, beckoning for speed. She quickened her pace. Dawn birds already were calling and lifting into the sky. A dim spread of light grew across the eastern horizon.
The figure above was not one of her own escort. Otheym? she wondered, marking a familiarity of movement and manner. She came up to him, recognized in the growing light the broad, flat features of the Fedaykin lieutenant, his hood open and mouth filter loosely fastened the way one did sometimes when venturing out on the desert for only a moment.
"Hurry," he hissed, and led her down the secret crevasse into the hidden cave. "It will be light soon," he whispered as he held a doorseal open for her. "The Harkonnens have been making desperation patrols over some of this region. We dare not chance discovery now."
They emerged into the narrow side-passage entrance to the Cave of Birds . Glowglobes came alight. Otheym pressed past her, said: "Follow me. Quickly, now."
They sped down the passage, through another valve door, another passage and through hangings into what had been the Sayyadina's alcove in the days when this was an overday rest cave. Rugs and cushions now covered the floor. Woven hangings with the red figure of a hawk hid the rock walls. A low field desk at one side was strewn with papers from which lifted the aroma of their spice origin.
The Reverend Mother sat alone directly opposite the entrance. She looked up with the inward stare that made the uninitiated tremble.
Otheym pressed palms together, said: "I have brought Chani." He bowed, retreated through the hangings.
And Jessica thought: How do I tell Chani?
"How is my grandson?" Jessica asked.
So it's to be the ritual greeting , Chani thought, and her fears returned. Where is Muad'Dib? Why isn't he here to greet me?
"He is healthy and happy, my mother," Chani said. "I left him with Alia in the care of Harah."
My mother , Jessica thought. Yes, she has the right to call me that in the formal greeting. She has given me a grandson .
"I hear a gift of cloth has been sent from Coanua sietch," Jessica said.
"It is lovely cloth," Chani said.
"Does Alia send a message?"
"No message. But the sietch moves more smoothly now that the people are beginning to accept the miracle of her status."
Why does she drag this out so? Chani wondered. Something was so urgent that they sent a 'thopter for me. Now, we drag through the formalities!
"We must have some of the new cloth cut into garments for little Leto," Jessica said.
"Whatever you wish, my mother," Chani said. She lowered her gaze. "Is there news of battles?" She held her face expressionless that Jessica might not see the betrayal—that this was a question about Paul Muad'Dib.
"New victories," Jessica said. "Rabban has sent cautious overtures about a truce. His messengers have been returned without their water. Rabban has even lightened the burdens of the people in some of the sink villages. But he is too late. The people know he does it out of fear of us."
"Thus it goes as Muad'Dib said," Chani said. She stared at Jessica, trying to keep her fears to herself. I have spoken his name, but she has not responded. One cannot see emotion in that glazed stone she calls a face . . . but she is too frozen. Why is she so still? What has happened to my Usul?
"I wish we were in the south," Jessica said. "The oases were so beautiful when we left. Do you not long for the day when the whole land may blossom thus?"
"The land is beautiful, true," Chani said. "But there is much grief in it."
"Grief is the price of victory," Jessica said.