“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 assumed 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 superstition 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 Mechanicum 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.”