Leto stood in the foyer of his house, studying a note by the light of a single suspensor lamp. Dawn was yet a few hours away, and he felt his tiredness. A Fremen messenger had brought the note to the outer guard just now as the Duke arrived from his command post.

The note read: "A column of smoke by day, a pillar of fire by night."

There was no signature.

What does it mean? he wondered.

The messenger had gone without waiting for an answer and before he could be questioned. He had slipped into the night like some smoky shadow.

Leto pushed the paper into a tunic pocket, thinking to show it to Hawat later. He brushed a lock of hair from his forehead, took a sighing breath. The anti-fatigue pills were beginning to wear thin. It had been a long two days since the dinner party and longer than that since he had slept.

On top of all the military problems, there'd been the disquieting session with Hawat, the report on his meeting with Jessica.

Should I waken Jessica? he wondered. There's no reason to play the secrecy game with her any longer. Or is there?

Blast and damn that Duncan Idaho!

He shook his head. No, not Duncan. I was wrong not to take Jessica into my confidence from the first. I must do it now, before more damage is done .

The decision made him feel better, and he hurried from the foyer through the Great Hall and down the passages toward the family wing.

At the turn where the passages split to the service area, he paused. A strange mewling came from somewhere down the service passage. Leto put his left hand to the switch on his shield belt, slipped his kindjal into his right hand. The knife conveyed a sense of reassurance. That strange sound had sent a chill through him.

Softly, the Duke moved down the service passage, cursing the inadequate illumination. The smallest of suspensors had been spaced about eight meters apart along here and tuned to their dimmest level. The dark stone walls swallowed the light.

A dull blob stretching across the floor appeared out of the gloom ahead.

Leto hesitated, almost activated his shield, but refrained because that would limit his movements, his hearing... and because the captured shipment of lasguns had left him filled with doubts.

Silently, he moved toward the grey blob, saw that it was a human figure, a man face down on the stone. Leto turned him over with a foot, knife poised, bent close in the dim light to see the face. It was the smuggler, Tuek, a wet stain down his chest. The dead eyes stared with empty darkness. Leto touched the stain—warm.

How could this man be dead here? Leto asked himself. Who killed him?

The mewling sound was louder here. It came from ahead and down the side passage to the central room where they had installed the main shield generator for the house.

Hand on belt switch, kindjal poised, the Duke skirted the body, slipped down the passage and peered around the corner toward the shield generator room.

Another grey blob lay stretched on the floor a few paces away, and he saw at once this was the source of the noise. The shape crawled toward him with painful slowness, gasping, mumbling.

Leto stilled his sudden constriction of fear, darted down the passage, crouched beside the crawling figure. It was Mapes, the Fremen housekeeper, her hair tumbled around her face, clothing disarrayed. A dull shininess of dark stain spread from her back along her side. He touched her shoulder and she lifted herself on her elbows, head tipped up to peer at him, the eyes black-shadowed emptiness.

"S'you," she gasped. "Killed... guard... sent... get... Tuek... escape... m'Lady... you... you... here... no... " She flopped forward, her head thumping against the stone.

Leto felt for pulse at the temples. There was none. He looked at the stain: she'd been stabbed in the back. Who? His mind raced. Did she mean someone had killed a guard? And Tuek—had Jessica sent for him? Why?

He started to stand up. A sixth sense warned him. He flashed a hand toward the shield switch—too late. A numbing shock slammed his arm aside. He felt pain there, saw a dart protruding from the sleeve, sensed paralysis spreading from it up his arm. It took an agonizing effort to lift his head and look down the passage.

Yueh stood in the open door of the generator room. His face reflected yellow from the light of a single, brighter suspensor above the door. There was stillness from the room behind him—no sound of generators.

Yueh! Leto thought. He's sabotaged the house generators! We 're wide open!

Yueh began walking toward him, pocketing a dartgun.

Leto found he could still speak, gasped: "Yueh! How?" Then the paralysis reached his legs and he slid to the floor with his back propped against the stone wall.

Yueh's face carried a look of sadness as he bent over, touched Leto's forehead. The Duke found he could feel the touch, but it was remote... dull.

"The drug on the dart is selective," Yueh said "You can speak, but I'd advise against it." He glanced down the hall, and again bent over Leto, pulled out the dart, tossed it aside. The sound of the dart clattering on the stones was faint and distant to the Duke's ears.

It can't be Yueh , Leto thought. He's conditioned.

"How?" Leto whispered.

"I'm sorry, my dear Duke, but there are things which will make greater demands than this." He touched the diamond tattoo on his forehead. "I find it very strange, myself—an override on my pyretic conscience—but I wish to kill a man. Yes, I actually wish it. I will stop at nothing to do it."

He looked down at the Duke. "Oh, not you, my dear Duke. The Baron Harkonnen. I wish to kill the Baron."

"Bar... on Har... "

"Be quiet, please, my poor Duke. You haven't much time. That peg tooth I put in your mouth after the tumble at Narcal—that tooth must be replaced, in a moment, I'll render you unconscious and replace that tooth." He opened his hand, stared at something in it. "An exact duplicate, its core shaped most exquisitely like a nerve. It'll escape the usual detectors, even a fast scanning. But if you bite down hard on it, the cover crushes. Then, when you expel your breath sharply, you fill the air around you with a poison gas—most deadly."

Leto stared up at Yueh, seeing madness in the man's eyes, the perspiration along brown and chin.

"You were dead anyway, my poor Duke," Yueh said. "But you will get close to the Baron before you die. He'll believe you're stupefied by drugs beyond any dying effort to attack him. And you will be drugged—and tied. But attack can take strange forms. And you will remember the tooth. The tooth , Duke Leto Atreides. You will remember the tooth."

The old doctor leaned closer and closer until his face and drooping mustache dominated Leto's narrowing vision.

"The tooth," Yueh muttered.

"Why?" Leto whispered.

Yueh lowered himself to one knee beside the Duke. "I made a shaitan's bargain with the Baron. And I must be certain he has fulfilled his half of it. When I see him, I'll know. When I look at the Baron, then I will know. But I'll never enter his presence without the price. You're the price, my poor Duke. And I'll know when I see him. My poor Wanna taught me many things, and one is to see certainty of truth when the stress is great. I cannot do it always, but when I see the Baron—then, I will know."