Above all else, Muad'dib was the kwisatz haderach which the Sisterhood's breeding program had sought across thousands of generations.

The kwisatz haderach, then, the one who could be "many places at once," this prophet, this man through whom the Bene Gesserit hoped to control human destiny - this man became Emperor Muad'dib and executed a marriage of convenience with a daughter of the Padishah Emperor he had defeated.

Think on the paradox, the failure implicit in this moment, for you surely have read other histories and know the surface facts. Muad'dib's wild Fremen did, indeed, overwhelm the Padishah Shaddam IV. They toppled the Sardaukar legions, the allied forces of the Great Houses, the Harkonnen armies and the mercenaries bought with money voted in the Landsraad. He brought the Spacing Guild to its knees and placed his own sister, Alia, on the religious throne the Bene Gesserit had thought their own.

He did all these things and more.

Muad'dib's Qizarate missionaries carried their religious war across space in a Jihad whose major impetus endured only twelve standard years, but in that time, religious colonialism brought all but a fraction of the human universe under one rule.

He did this because capture of Arrakis, that planet known more often as Dune, gave him a monopoly over the ultimate coin of the realm - the geriatric spice, melange, the poison that gave life.

Here was another ingredient of ideal history: a material whose psychic chemistry unraveled Time. Without melange, the Sisterhood's Reverend Mothers could not perform their feats of observation and human control. Without melange, the Guild's Steersmen could not navigate across space. Without melange, billions upon billions of Imperial citizens would die of addictive withdrawal.

Without melange, Paul-Muad'dib could not prophesy.

We know this moment of supreme power contained failure. There can be only one answer, that completely accurate and total prediction is lethal.

Other histories say Muad'dib was defeated by obvious plotters - the Guild, the Sisterhood and the scientific amoralists of the Bene Tleilex with their Face-Dancer disguises. Other histories point out the spies in Muad'dib's household. They make much of the Dune Tarot which clouded Muad'dib's powers of prophecy. Some show how Muad'dib was made to accept the services of a ghola, the flesh brought back from the dead and trained to destroy him. But certainly they must know this ghola was Duncan Idaho, the Atreides lieutenant who perished saving the life of the young Paul.

Yet, they delineate the Qizarate cabal guided by Korba the Panegyrist. They take us step by step through Korba's plan to make a martyr of Muad'dib and place the blame on Chani, the Fremen concubine.

How can any of this explain the facts as history has revealed them? They cannot. Only through the lethal nature of prophecy can we understand the failure of such enormous and far-seeing power.

Hopefully, other historians will learn something from this revelation.

Despite the murderous nature of the plot he hoped to devise, the thoughts of Scytale, the Tleilaxu Face Dancer, returned again and again to rueful compassion.

I shall regret causing death and misery to Muad'dib, he told himself.

He kept this benignity carefully hidden from his fellow conspirators. Such feelings told him, though, that he found it easier to identify with the victim than with the attackers - a thing characteristic of the Tleilaxu.

Scytale stood in bemused silence somewhat apart from the others. The argument about psychic poison had been going on for some time now. It was energetic and vehement, but polite in that blindly compulsive way adepts of the Great Schools always adopted for matters close to their dogma.

"When you think you have him skewered, right then you'll find him unwounded!"

That was the old Reverend Mother of the Bene Gesserit, Gaius Helen Mohiam, their hostess here on Wallach IX. She was a black-robed stick figure, a witch crone seated in a floater chair at Scytale's left. Her aba hood had been thrown back to expose a leathery face beneath silver hair. Deeply pocketed eyes stared out of skull-mask features.

They were using a mirabhasa language, honed phalange consonants and joined vowels. It was an instrument for conveying fine emotional subtleties. Edric, the Guild Steersman, replied to the Reverend Mother now with a vocal curtsy contained in a sneer - a lovely touch of disdainful politeness.

Scytale looked at the Guild envoy. Edric swam in a container of orange gas only a few paces away. His container sat in the center of the transparent dome which the Bene Gesserit had built for this meeting. The Guildsman was an elongated figure, vaguely humanoid with finned feet and hugely fanned membranous hands - a fish in a strange sea. His tank's vents emitted a pale orange cloud rich with the smell of the geriatric spice, melange.

"If we go on this way, we'll die of stupidity!"

That was the fourth person present - the potential member of the conspiracy - Princess Irulan, wife (but not mate, Scytale reminded himself) of their mutual foe. She stood at a corner of Edric's tank, a tall blond beauty, splendid in a robe of blue whale fur and matching hat. Gold buttons glittered at her ears. She carried herself with an aristocrat's hauteur, but something in the absorbed smoothness of her features betrayed the controls of her Bene Gesserit background.

Scytale's mind turned from nuances of language and faces to nuances of location. All around the dome lay hills mangy with melting snow which reflected mottled wet blueness from the small blue-white sun hanging at the meridian.

Why this particular place? Scytale wondered. The Bene Gesserit seldom did anything casually. Take the dome's open plan: a more conventional and confining space might've inflicted the Guildsman with claustrophobic nervousness. Inhibitions in his psyche were those of birth and life off-planet in open space.

To have built this place especially for Edric, though - what a sharp finger that pointed at his weakness.

What here, Scytale wondered, was aimed at me?

"Have you nothing to say for yourself, Scytale?" the Reverend Mother demanded.

"You wish to draw me into this fools' fight?" Scytale asked. "Very well. We're dealing with a potential messiah. You don't launch a frontal attack upon such a one. Martyrdom would defeat us."

They all stared at him.

"You think that's the only danger?" the Reverend Mother demanded, voice wheezing.

Scytale shrugged. He had chosen a bland, round-faced appearance for this meeting, jolly features and vapid full lips, the body of a bloated dumpling. It occurred to him now, as he studied his fellow conspirators, that he had made an ideal choice - out of instinct perhaps. He alone in this group could manipulate fleshly appearance across a wide spectrum of bodily shapes and features. He was the human chameleon, a Face Dancer, and the shape he wore now invited others to judge him too lightly.

"Well?" the Reverend Mother pressed.

"I was enjoying the silence," Scytale said. "Our hostilities are better left unvoiced."

The Reverend Mother drew back, and Scytale saw her reassessing him. They were all products of profound prana-bindu training, capable of muscle and nerve control that few humans ever achieved. But Scytale, a Face Dancer, had muscles and nerve linkages the others didn't even possess plus a special quality of sympatico, a mimic's insight with which he could put on the psyche of another as well as the other's appearance.