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

Well, no matter now , the Baron thought, his mind firming. The next guard captain will begin by finding answers to these questions .
He grew aware of more activity down the hall—around the corner at the other door to that room of death. The Baron pushed himself away from his own door, studied the lackeys around him. They stood there staring, silent, waiting for the Baron's reaction.
Would the Baron be angry?
And the Baron realized only a few seconds had passed since his flight from that terrible room.
Some of the guards had weapons leveled at the door. Some were directing their ferocity toward the empty hall that stretched away toward the noises around the corner to their right.
A man came striding around that corner, gas mask dangling by its straps at his neck, his eyes intent on the overhead poison snoopers that lined this corridor. He was yellow-haired, flat of face with green eyes. Crisp lines radiated from his thick-lipped mouth. He looked like some water creature misplaced among those who walked the land.
The Baron stared at the approaching man, recalling the name: Nefud . Iakin Nefud. Guard corporal. Nefud was addicted to semuta, the drug-music combination that played itself in the deepest consciousness. A useful item of information, that.
The man stopped in front of the Baron, saluted. "Corridor's clear, m'Lord. I was outside watching and saw that it must be poison gas. Ventilators in your room were pulling air in from these corridors." He glanced up at the snooper over the Baron's head. "None of the stuff escaped. We have the room cleaned out now. What are your orders?"
The Baron recognized the man's voice—the one who'd been shouting orders. Efficient, this corporal , he thought.
"They're all dead in there?" the Baron asked.
"Yes, m'Lord."
Well, we must adjust , the Baron thought.
"First," he said, "let me congratulate you, Nefud . You're the new captain of my guard. And I hope you'll take to heart the lesson to be learned from the fate of your predecessor."
The Baron watched the awareness grow in his newly promoted guardsman. Nefud knew he'd never again be without his semuta.
Nefud nodded. "My Lord knows I'll devote myself entirely to his safety."
"Yes. Well, to business. I suspect the Duke had something in his mouth. You will find out what that something was, how it was used, who helped him put it there. You'll take every precaution—"
He broke off, his chain of thought shattered by a disturbance in the corridor behind him—guards at the door to the lift from the lower levels of the frigate trying to hold back a tall colonel bashar who had just emerged from the lift.
The Baron couldn't place the colonel bashar's face: thin with mouth like a slash in leather, twin ink spots for eyes.
"Get your hands off me, you pack of carrion-eaters!" the man roared, and he dashed the guards aside.
Ah-h-h, one of the Sardaukar , the Baron thought.
The colonel bashar came striding toward the Baron, whose eyes went to slits of apprehension. The Sardaukar officers filled him with unease. They all seemed to look like relatives of the Duke . . . the late Duke. And their manners with the Baron!
The colonel bashar planted himself half a pace in front of the Baron, hands on hips. The guard hovered behind him in twitching uncertainty.
The Baron noted the absence of salute, the disdain in the Sardaukar's manner, and his unease grew. There was only the one legion of them locally—ten brigades—reinforcing the Harkonnen legions, but the Baron did not fool himself. That one legion was perfectly capable of turning on the Harkonnens and overcoming them.
"Tell your men they are not to prevent me from seeing you, Baron," the Sardaukar growled. "My men brought you the Atreides Duke before I could discuss his fate with you. We will discuss it now."
I must not lose face before my men , the Baron thought.
"So?" It was a coldly controlled word, and the Baron felt proud of it.
"My Emperor has charged me to make certain his royal cousin dies cleanly without agony," the colonel bashar said.
"Such were the Imperial orders to me," the Baron lied. "Did you think I'd disobey?"
"I'm to report to my Emperor what I see with my own eyes," the Sardaukar said.
"The Duke's already dead," the Baron snapped, and he waved a hand to dismiss the fellow.
The colonel bashar remained planted facing the Baron. Not by flicker of eye or muscle did he acknowledge he had been dismissed. "How?" he growled.