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

He's most likely correct , Leto thought. Were if not for the tooth . . . and the fact that I truly don't know where they are .
The Baron picked up a sliver of meat, pressed the morsel into his mouth, chewed slowly, swallowed. We must try a new tack , he thought.
"Observe this prize person who denies he's for hire," the Baron said. "Observe him, Piter."
And the Baron thought: Yes! See him there, this man who believes he cannot be bought. See him detained there by a million shares of himself sold in dribbles every second of his life! If you took him up now and shook him, he'd rattle inside. Emptied! Sold out! What difference how he dies now?
The frog sounds in the background stopped.
The Baron saw Umman Kudu, the guard captain, appear in the doorway across the room, shake his head. The captive hadn't produced the needed information. Another failure. Time to quit stalling with this fool Duke, this stupid soft fool who didn't realize how much hell there was so near him—only a nerve's thickness away.
This thought calmed the Baron, overcoming his reluctance to have a royal person subject to pain. He saw himself suddenly as a surgeon exercising endless supple scissor dissections—cutting away the masks from fools, exposing the hell beneath.
Rabbits, all of them!
And how they cowered when they saw the carnivore!
Leto stared across the table, wondering why he waited. The tooth would end it all quickly. Still—it had been good, much of this life. He found himself remembering an antenna kite updangling in the shell-blue sky of Caladan, and Paul laughing with joy at the sight of it. And he remembered sunrise here on Arrakis—colored strata of the Shield Wall mellowed by dust haze.
"Too bad," the Baron muttered. He pushed himself back from the table, stood up lightly in his suspensors and hesitated, seeing a change come over the Duke. He saw the man draw in a deep breath, the jawline stiffen, the ripple of a muscle there as the Duke clamped his mouth shut.
How he fears me! the Baron thought.
Shocked by fear that the Baron might escape him, Leto bit sharply on the capsule tooth, felt it break. He opened his mouth, expelled the biting vapor he could taste as it formed on his tongue. The Baron grew smaller, a figure seen in a tightening tunnel. Leto heard a gasp beside his ear—the silky-voiced one: Piter.
It got him, too!
"Piter! What's wrong?"
The rumbling voice was far away.
Leto sensed memories rolling in his mind—the old toothless mutterings of hags. The room, the table, the Baron, a pair of terrified eyes—blue within blue, the eyes—all compressed around him in ruined symmetry.
There was a man with a boot-toe chin, a toy man falling. The toy man had a broken nose slanted to the left: an offbeat metronome caught forever at the start of an upward stroke. Leto heard the crash of crockery—so distant—a roaring in his ears. His mind was a bin without end, catching everything. Everything that had ever been: every shout, every whisper, every . . . silence.
One thought remained to him. Leto saw it in formless light on rays of black: The day the flesh shapes and the flesh the day shapes . The thought struck him with a sense of fullness he knew he could never explain.
Silence.
The Baron stood with his back against his private door, his own bolt hole behind the table. He had slammed it on a room full of dead men. His senses took in guards swarming around him. Did I breathe it? he asked himself. Whatever it was in there, did it get me, too?
Sounds returned to him . . . and reason. He heard someone shouting orders—gas masks . . . keep a door closed . . . get blowers going.
The others fell quickly , he thought. I'm still standing. I'm still breathing. Merciless hell! That was close!
He could analyze it now. His shield had been activated, set low but still enough to slow molecular interchange across the field barrier. And he had been pushing himself away from the table . . . that and Piter's shocked gasp which had brought the guard captain darting forward into his own doom.
Chance and the warning in a dying man's gasp—these had saved him.
The Baron felt no gratitude to Piter. The fool had got himself killed. And that stupid guard captain! He'd said he scoped everyone before bringing them into the Baron's presence! How had it been possible for the Duke . . . ? No warning. Not even from the poison snooper over the table—until it was too late. How?