"He died, a long time ago."

"I'm sorry to hear that," said Lemuel, finding the notion that Astartes warriors had lives before their transformation into super-engineered post-humans something he hadn't considered. Such were the enormous divergences from the human norm that it was easier to a.s.sume the Astartes sprang full-grown from some secret laboratory. It put a human face on an inhuman creation to know that Ahriman had once had a brother, a relationship that most mortals took for granted.

"What was his name?"

"He was called Ohrmuzd, which means *sacrifice' in the ancient tongue of the Avesta."

"Why are you telling me this?"

"Because it will be useful," said Ahriman. "For both of us, I think. The doom of Ohrmuzd is also the story of how the Thousand Sons came to be. Do you wish to hear of it?"

"I do," said Lemuel.

"FROM THE VERY beginning, we were a troubled Legion," said Ahriman. "The primarch tells me our gene-stock was harvested at an inauspicious time, a time of great cosmic upheaval. The warp storms that had all but isolated Terra in the lightless age of strife were resurgent once more and the effects were felt all across the world: madness, suicide and senseless violence. The last of the pan-continental despots had been toppled and the world was only just lifting its head from the ashes of that global conflict. It seemed like these were the last, dying paroxysms of the wars, which was true to an extent, but there was more to it than that."

"You were there?" asked Lemuel. "To see all that?"

"No, but I was a quick learner. I was one of the lucky ones, conceived and born among the wealthy tribes of the Achaemenid Empire. Our kings had allied with Earth's new master more than a century before, and we were spared the horrors of atomic war or the invasion of the Thunder-armoured warriors."

"The proto-Astartes."

Ahriman nodded, saying, "Brutal and unsubtle creations, but sufficient for the job of conquest. They were ordinary men, the fiercest warriors of the Emperor, within whose bodies he had implanted full-grown biological hardware and mechanical augmentations to boost their strength, endurance and speed. They were monstrous things, and most were eventually driven insane by the demands their enhanced physiques made upon them."

Lemuel noticed the inflexion Ahriman put on the word enhanced, reading his thinly-veiled criticism of the Emperor's first creations.

"With the end of the wars, the Emperor tightened his grip on Terra and turned his gaze to the heavens, knowing that he had achieved only the first step on the road to Unity. He knew the Thunder Warriors would never be able to join him on his quest to unite the disparate threads of humanity and bind them together once again. He would need another army, an army as superior to the Thunder Warriors as they were superior to mortal men. But first he would need generals, mighty soldiers who could lead them in battle."

"You're talking about the primarchs, aren't you?"

"I am, yes. The Emperor created the primarchs using lost science and technology he had uncovered in his long wars. With the aid of rogue geneticists from the Martian Hegemony, he crafted beings of such luminosity that their like could never be conjured again. They were the pinnacles of genetic evolution, but they were lost to the Emperor before they could reach maturity. You have heard the legends, surely?"

"I have, but I a.s.sumed they were just that, legends."

"No," said Ahriman, shaking his head. "They are truths enhanced by myths to allow men to better immortalise their deeds. It is far easier to march into the fires of war following a warrior whose origins are legendary than one who has no such glorious pedigree."

"I suppose so," agreed Lemuel. "I hadn't thought of it like that."

"Few do," said Ahriman with a smile. "But I was talking about me."

"Sorry, go on."

"My people's biological heritage was uncontaminated by many of the inherited flaws and viral defects so common to the other tribes of Earth, so the Emperor walked among us with his army of scientists, testing each and every family grouping for the requisite genetic markers. In my brother and I, he found what he was looking for and, with my parent's blessing, took Ohrmuzd and I to a secret place deep within the high mountains at the crown of the world. Before we left, our mother gave each of us one of these talismans, said to represent the strength of Dhul-Qarnayn, the greatest ruler of the Achaemenid. She bade us keep them close, telling us that the power of the ancient king would keep us safe."

Ahriman pulled a leather cord from around his neck, revealing a silver pendant the size of a coin upon which was embossed the image of an oak leaf. It was the twin of the one set in Ahriman's shoulder-guard.

"Foolish superst.i.tion of course. How could a king who has been dust for tens of thousands of years protect the living? Though it went against the new creed of reason, we kept our talismans close throughout our training."

"What sort of training?"

"Tests of strength, speed and mental agility. From an early age, the people of my culture were taught to value truth over all things, and Ohrmuzd and I were the sons of royalty, so we had long since learned to hunt and kill and debate. We excelled in all aspects of our training, and our biological advancement was a source of great pleasure to the scientists who attended us and monitored our progress. There were many of us training beneath the mountains, but gradually we were channelled into different groups, and Ohrmuzd and I were overjoyed at being kept together while many other siblings were split up.

"We grew rapidly and trained harder than any have trained before or since. Our prowess was unmatched and we marched into battle to quell the last pockets of resistance and rebellion on Terra to test our battle skills. Armoured in the latest battle-plate and equipped with the most destructive weapons, none could match us, and we were named the Thousand Sons.

"When the time came to leave Terra, it was a great moment. Not even the triumph at Ullanor can compare with the moment of grief as an entire world wept to see the architect of Unification depart. The alliance of Terra and Mars was complete, and the Mechanic.u.m had outdone itself, building fleets of ships to allow the Emperor to take to the stars and complete his Great Crusade of Unity. The skies over Terra were thick with starships, hundreds of thousands of them organised into more than seven thousand fleets, reserve groups and secondary, follow-on forces. It was an armada designed to conquer the galaxy and that was exactly what we set out to do."

Ahriman paused in his tale to look out over Tizca far below, his eyes lifting to the black mirror of the ocean. Lemuel saw a faraway look in his eyes, and had the powerful sense that Ahriman was telling this tale as much for his own benefit as for Lemuel's.

"The early years of the Crusade were a joy to us, a time of war and conquest as we swept through the solar system and reclaimed it once more. Beyond the boundaries of Terra, hostile xenos species had taken root, and we culled them without mercy, blackening their worlds and leaving nothing in our wake but ashes."

"That doesn't sound like the Great Crusade," pointed out Lemuel. "I thought it was all about enlightenment and the advance of reason. That sounds like conquest for the sake of it."

"You have to understand that we were fighting for the survival of the species then. Terra was surrounded on all sides by predatory races, and to survive we fought fire with fire. It was a glorious time, where the Astartes learned of the sheer, unstoppable fury we could bring to bear. War forges a man's character, and that is no less true of a Legion. Whether it was the echoes of our gene-sires in our blood, I do not know, but each of the Legions began to take shape beyond simply a name. The Ultramarines gained a reputation for order and discipline, fighters who learned from each engagement and applied that knowledge to the next. The World Eaters, well, you can imagine how they learned to fight."

"And the Thousand Sons?"

"Ah... There we come to the first cracks in our great adventure," said Ahriman.

"Cracks?"

"Our character manifested itself five years into the crusade. Our warriors began to display abilities far beyond anything we had expected. I could see things before they happened, and Ohrmuzd could craft lightning from the air. Others amongst our Legion could perform similar feats. At first we were jubilant, thinking this to be latent power encoded into our genes by the Emperor, but soon our joy turned to horror as first one warrior, then more began to change."

"Like Hastar on Shrike," said Lemuel.

"The flesh change, yes," said Ahriman, rising and moving to the edge of the arboretum. Ahriman gripped the railing, staring off into the far distance. Lemuel joined him, fighting off mild vertigo as he looked down.

"The first warrior died on Bezant, his flesh turned inside out and his powers beyond his control. Something took his flesh, ripped him apart and made him a vessel for a xenos beast from the Great Ocean. We thought this was just a fluke occurrence, but it was not; it was an epidemic."

"It was really that bad?"

"It was worse than you can imagine," said Ahriman, and Lemuel believed him. "It was not long before others noticed it. Many of the Legions had been reunited with their sires, and some of them found the notion of our powers to be hateful. Mortarion was the worst, but Corax and Dorn were not much better. They feared what we could do, and spread their lies to anyone who would listen that we were witches practising unclean sorcery. Little did any of them realise they were condemning the very powers that allowed them to travel between the stars or spread their malicious rumour-mongering."

Lemuel saw the anger in Ahriman's face, the bitterness of memory causing the plants nearby to wither and blacken. He felt a nauseous twist in his gut and swallowed a mouthful of bile as Ahriman continued.

"With every pa.s.sing year, more and more of our warriors would succ.u.mb to the flesh change, though we grew ever more adept at spotting the signs and taking steps to contain them. Perversely, the more warriors suffered the change, the stronger our powers became. We learned how to keep the worst of the flesh change at bay, but more and more of us were falling prey to it and the voices of our persecutors were growing ever more strident. There was even talk of disbanding us and expunging us from Imperial history."

Lemuel shook his head.

"That's the thing about history," he said. "It has a habit of remembering the things you'd like to forget. No one can erase that much, there will always be some record."

"Don't be so sure, Lemuel," said Ahriman. "The Emperor's wrath is a terrible thing."

Lemuel heard the sorrow in Ahriman's voice and wanted to ask more, but the tale was not yet done.

"Ohrmuzd and I were at the forefront of the Thousand Sons, its greatest warriors and most powerful pract.i.tioners of the arts. We thought we were immune to the flesh change, that our power was too great for it to touch us. How arrogant we were! Ohrmuzd fell prey to its effects first, and I was forced to secure him as he fought against his rebelling flesh."

Ahriman turned to Lemuel, and Lemuel quailed before the intensity of his gaze.

"Imagine your body turning on you, every molecule refusing to hold to its genetically-encoded purpose, with only your strength of will preventing your flesh from uncontrollably mutating, all the while knowing that eventually you must weaken and it will take you."

"I can't," said Lemuel. "It's beyond me."

"I did what I could for Ohrmuzd, but soon after his succ.u.mbing, I too was afflicted. I did not go into stasis with the rest of our fallen brothers, doomed to wait out the entirety of the Great Crusade until a cure could be found, for I was able to stave off the change, though it was a battle I knew I was destined to lose."

Ahriman smiled, and the twisting pain in Lemuel's guts subsided.

"Then, a miracle happened," he said. "We reached Prospero and the Emperor found Magnus."

"What was it like?" asked Lemuel. "To be reunited with your lost sire?"

"Magnus was our salvation," said Ahriman, with no small amount of pride. "We descended to the planet's surface at the Emperor's side, though I remember little of the first meeting of father and son, for my body was wracked with pain as I fought to hold myself together. It was a dark time for our Legion, and yet a joyous one. It was clear to us that we could not go on as we were, for the flesh change was taking too many of us, and there was nothing we could do to stop it. Even as we despaired, we rejoiced, for we were finally reunited with the genetic father of our Legion."

Lemuel smiled to hear the fond recollection in Ahriman's voice. The Captain of the 1st Fellowship looked over to the Pyramid of Photep, and an unreadable expression crossed his face, like a man afraid to face a guilty memory he has buried deep.

"Within a day of the Emperor leaving Prospero, more and more of the Legion fell prey to the change. Though I had resisted it longer than any other had before, I too succ.u.mbed and my body began to rebel. My powers raged uncontrolled, but all I remember of that day is the horror of knowing that soon I would be little better than some of the monstrous things we had slain in our expansion from Terra. Soon, I would need to be put down like a beast.

"Then I remember a soothing voice in my head, soft and silky, like I imagined a father's would be when comforting a sick child. Darkness stole over me, and when I awoke, my physique was unblemished and without a mark. The flesh change had almost destroyed us, yet we were whole and in control of our bodies once more. The Legion had been saved, but I felt no joy that day, for a piece of me had died."

"Your twin brother," said Lemuel.

"Yes. I was whole, but Ohrmuzd had died. His body was too ravaged by the flesh change, and nothing could be done to save him," said Ahriman. "I took his silver oakleaf and incorporated it into my armour. His memory deserved no less."

"Again, you have my condolences," said Lemuel.

"None of us could recall anything of how this miracle came to pa.s.s, but we were alive, though barely a thousand of us were left."

"The Legion name," said Lemuel.

"Literally," agreed Ahriman. "Now we truly were the Thousand Sons."

Lemuel frowned and said, "Wait, that doesn't make sense. You were known as the Thousand Sons before you reached Prospero, yes?"

"Yes."

"Why?"

"Why what?"

"Why that name in particular? The Legion's name only makes sense after Magnus saved you on Prospero," said Lemuel. "Yet you were known as the Thousand Sons before then. So is it just a stupendous coincidence that there happened only to be a thousand survivors?"

"Now you are thinking like a Practicus," said Ahriman with a smile. "I keep telling you that there is no such thing as coincidence."

"So what are you telling me? That the Emperor saw what was happening to you and knew that Magnus would save a thousand of you?"

"Perhaps. The Emperor has seen a great many things," said Ahriman, though Lemuel sensed evasion in his words. "Yes, Magnus saved us, but he never said how he did it."

"Does it matter?" asked Lemuel. "He saved you. Isn't that enough?"

Ahriman turned his gaze to the heavens. "That remains to be seen, but I think it will matter. I think it will matter a great deal."

AS MUCH AS she was worried about Kallista, Camille was relishing her day of exploration too much to worry about her stricken friend. She had rolled out of bed, kissed Chaiya goodbye, and made her way to the rendezvous with Khalophis without so much as a second thought for Kallista Eris. She felt guilty about that, but not so guilty she was going to miss out on the chance of exploring the Desolation of Prospero.

Khalophis' disc-speeder brought them to the ruined city in less than an hour, which had disappointed Camille until he told her how far and fast they had travelled. Tizca was far behind them, and she wondered why everyone still called the lands beyond Tizca the "Desolation", as nothing could be further from the truth. The landscape was as lush as anything she could ever imagine. Vast forests and wide open plains spread to the horizons, and crystal clear rivers spilled in foaming waterfalls from the mountains.

Khalophis had steered the speeder with delicate skill, which she found surprising. She expected him to fly brusquely and without finesse. The sense of speed as they flew through this bountiful land had been exhilarating, and the thrill of being allowed to explore the far cities of Prospero was as close to perfect as she could imagine.

Camille looked up at the high stacks of blackened iron and stone towering above her. Their structures were wrapped in greenery and swayed gently in the chill winds funnelled down from the end of the valley. Hundreds of skeletal frames arranged in what looked like grid patterns dotted the valley mouth, and the ground underfoot was like faded rockcrete, cracked and split by patient weeds.

Broken piles of stone cl.u.s.tered the bases of the structures, like cladding or flooring pushed from the structures they had once enclosed by the relentless forces of nature.

Over the course of the morning and early afternoon, they had discovered some that still had elements of their internal structure intact, but these were few and far between.

Khalophis followed her, his boltgun slung casually over his shoulder as he watched her capturing pict images of the structures. She already had a library's worth of images, but the things she had touched so far had yielded little of interest.

"Have you found anything yet?" asked Khalopis. "These ruins bore me."

"Nothing yet," said Camille.

"We should go. This valley has seen some psychneuein activity of late."

Lemuel had mentioned psychneuein once. They sounded vile, but with a warrior like Khalophis to protect her, she wasn't unduly worried.

"We can't go yet," she said, ducking into the shadows of a largely intact structure that echoed with shadows and decay. "So far, everything I've touched has been machine-formed and without memory. They're no use to me. This one's in pretty good condition, so it might house something of value."

The interior of the building stank of neglect and damp, its shadows refuges for the wild animals that called the Desolation of Prospero home. Light broke in through holes in the walls and speared down from above. Dust hung in the air, drifting motes of light in the splintered breeze.

Camille drew in a deep breath, tasting the age of the structure in the musty fragrances. There was history here, stories she could unlock if she could only find something that had once belonged to a living, breathing person.

"This way," she said, heading towards a sagging steel stairway that led to the next level.

"That doesn't look safe," said Khalophis, eyeing the rusted handrails.

"I'm touched by your concern," said Camille, "but it's lasted a thousand years like this. I expect it'll last another afternoon, don't you?"

"I don't know, I'm not an engineer."

She tried to figure out if he was joking, but gave up when his expression didn't change.

"Okay then," she said, turning away. "I've climbed my share of rickety stairs, and this one looks fine."

She turned and made her way upstairs, hoping that the forces of comedic timing weren't about to deposit her in a heap of broken stairs and embarra.s.sment. Fortunately, they held, though they creaked and groaned alarmingly as Khalophis put his weight on them.

The upper level was as desolate as the lower, the grey floor covered in dust, droppings and debris from the levels above. Most of the higher floors had collapsed, leaving the building as little more than a hollow chimney, with occasional nubs of floor slabs and structural spars jutting into thin air. Birds fluttered above, and she caught the faint rustle of wings from high up nests.

"What do you hope to find here?" asked Khalophis. "Everything's decayed. If there was something to be learned here, don't you think we would have found it by now?"

Camille flashed him a confident smile.

"You can't look the way I can," she said.