Leo was eight years old. Physically, he resembled a well-built Terran adolescent, but his presence commanded respect far beyond his years. He stood on the northern perimeter wall of Bunker-7, arms crossed, watching the de-mining teams burn away the last traces of Creep after a particularly vicious night assault. The air reeked of charred chitin and superheated plasma.
In his mind, a very different battlefield was unfolding.
Flash. A monolithic fortress, its spires piercing an ashen sky. Warriors in crimson armor, marked with the symbol of a skull swallowed by a serpent, charged with silent fury. Their faces were masks of pure hatred. The word erupted in his head, laden with memetic poison: « Word Bearers ».
He blinked, shooing the vision away. It wasn't the first. For months, fragments had been returning, like shards of glass rising to the surface of troubled water. Images, sounds, names. Knowledge he had never learned on Tarsonis.
"Leo!" Marcus Valerius's gravelly voice sounded behind him. The Commander approached, his CMC armor covered in dust and soot. "You should be in tactical simulations with Major Kincaid."
"The simulations are inefficient," Leo replied without turning, his voice already deeper, shedding the last vestiges of childhood. "They are based on known Zerg patterns. They do not anticipate adaptation. The Tyranids of Hive Fleet Behemoth, for example, prioritize mass frontal assaults to overwhelm by numbers, while those of Hive Fleet Kraken favor encirclements and flanking attacks. Our defense protocols are identical for both. It is a mistake."
Valerius froze. "The… what? What are you talking about, son?"
Leo finally turned, his grey eyes seeming to see far beyond the base wall. "Tyranids. That is the true name of the Swarm. A consume-worlds xeno race, an incarnation of hunger from intergalactic space. The Zerg are… just a manifestation. A branch. Perhaps an escaped experiment. Their biological structure is 87.3% similar, but their evolutionary directive is different."
He spoke with absolute certainty, as if reciting incontestable historical facts. Valerius felt a chill run down his spine. This wasn't the language of an aspiring strategist. It was the language of an… apocalypse archivist.
"Leo… how can you know that?"
Flash. An infinite library, made of light and pure energy. Mountains of data scrolled past, imprinting themselves on his consciousness. The golden, terrible visage of a God-Emperor, not sitting on a throne, but walking among men, smiting entire armies with a gesture. « The Imperium of Man. » The name resonated like a funeral bell in his soul.
Leo brought a hand to his forehead, a slight pain piercing him. "I… I don't know. I just do. Like I know plasma overheats after seven sustained volleys without proper cooling. It is data." He looked at his adoptive father, a glimmer of confusion – a new emotion – in his steel gaze. "The memories… they are getting stronger."
Valerius placed a heavy hand on his shoulder. "Come with me."
He led him to his private quarters, away from prying ears. He took out a small metal box and retrieved the object he had recovered from the pod all those years ago: the shimmering cloth Leo had been lying on. He had always kept it, a silent talisman of the boy's mysterious origin.
"Perhaps this can help," he said simply, handing it to Leo.
Upon contact with the material, which was cold yet emitted a faint energy vibration, something broke in Leo's mind.
FLASH.
It wasn't a fragment. It was a tsunami.
Pain. Betrayal. The smell of blood and ozone. The roar of titanic weapon engines. He was no longer Leo Valerius, child of Tarsonis. He was… the Second. One of the Twenty. A son of the Emperor. He stood beside his brothers, giants in colored armor. He saw the wise Magnus discourse on the powers of the immaterium, the fiery Angron grinding his teeth, the noble Horus… Horus whose charm already masked the rot… And he knew his own name. His true name. The one given to him by his Father. But that name was covered in shame, in grief, a secret so terrible that the entire Legion had to be… expunged. History had forgotten it. The Great Error. The Horus Heresy. The death of the Imperium he had been created to serve and protect. He saw his Legion fight. And he saw his Legion die. Not to xenos, but to his battle-brothers. Expunged by those it was meant to protect. For a reason. A reason he knew, that burned at the core of his being like a black star. A fault so unforgivable it demanded annihilation.
Leo fell to his knees, a strangled cry in his throat. It wasn't a cry of physical pain, but the expression of a soul's agony, the pain of ten thousand years of repressed memory exploding at once.
"MY NAME!" he roared, his voice a distorted echo of what it once was, charged with primordial authority and suffering.
The bunker lights flickered. Computer systems stuttered, overwhelmed by an involuntary psychic emission. Somewhere, far out in the desert, a Zerg Pack Leader turned its hideous head towards the base, sensing a new, terrible, and ancient presence awakening.
Valerius was petrified, horrified and awestruck. He saw his son writhing on the floor, not like a child, but like a chained titan remembering its power.
Then, as suddenly as it came, it stopped.
Leo lay on the floor, breathing slowly. When he pushed himself up, his eyes had changed. The youthful curiosity was gone. In its place was the crushing weight of millennia, a tragic wisdom and a cold determination that chilled Valerius's blood.
He looked at the cloth, then at his father.
"They betrayed us all," he said, in a voice that was not quite his own. It was the voice of the Primarch remembering. "The Imperium I was born for is a rotting corpse, led by fanatics, feeding on the death of its own father."
He stood, his stature suddenly seeming far more imposing.
"But I am not dead. And now, I remember."
He stared at the wall, as if he could see through it, to the stars.
"Horus, Lorgar, Fulgrim…" The names fell from his lips like curses. "They defiled everything we fought for. They destroyed our legacy."
Then his gaze returned to Valerius, and a glimmer of the loyalty he had learned on Tarsonis softened the coldness in his eyes.
"But that is not my legacy. Not anymore. My legacy is here. It is this bunker. These soldiers. You."
He clenched the cloth in his fist.
"The Zerg are just a threat. Chaos… the true evil… is out there. But to face it, I must first save this world. I must forge a new legion. Not for a dead Emperor on a golden throne. But for the humanity that still survives."
For the first time, Leo Valerius, the rediscovered Primarch, smiled. It was not a joyful smile. It was the expression of a general who had just received the enemy's battle plans.
"And I know every weakness, every mistake, every secret of every being in this cursed galaxy. The war has just changed, father. For them."