Immaterium

Kayvaan gestured for him to continue, his expression tense.

The old man straightened, speaking with careful deliberation. "After the Horus Heresy, His Majesty the Emperor was interred on the Golden Throne. But the Golden Throne isn't merely a ceremonial seat. It's an ancient, arcane mechanism directly linked to the Astronomican. His Majesty's essence sustains the Astronomican, guiding the light that ensures safe passage through the Warp and shielding humanity from the horrors of Chaos. May the Emperor's eternal vigilance protect us all."

Kayvaan's eyes widened. "Are you saying these galaxies are so far away that even the Immaterium doesn't reach them?"

The old man met his gaze with a faint trace of pity. "It's complicated, but you can say yes. That's exactly what I'm saying."

The galaxy is now vast beyond comprehension, far too enormous for humanity to fully grasp. Take the Milky Way, for instance—it exists, sprawling and silent, doing nothing yet humbling in its sheer enormity. Even just the Milky Way alone could bring an empire to its knees, its size overwhelming enough to instill despair in humanity about its own insignificance.

In a city, you measure distances in meters as you walk. Traveling by car between cities? You'd use kilometers. But when you start thinking about traveling between stars or galaxies within the Milky Way, you measure in light-years. What's a light-year? It's the distance light travels in a straight line over the course of a year. Considering light can circle Terra seven and a half times in just one second, the distance it covers in a year is beyond staggering.

The closest galaxy to our solar system is Alpha Centauri, a triple-star system. Among its stars, Proxima Centauri is only 4.22 light-years away. That means even if we could travel at the speed of light, it would still take over four years to reach it.

Even with light-speed capabilities, traveling through the vastness of the galaxy is a journey of immense proportions. Thankfully, the universe we know isn't all there is. Our familiar cosmos is but a fragment of a greater existence. Beyond lies an independent, parallel dimension often referred to as "different space." People call it by many names depending on their culture—"chaos," "another world," "ether," or "Immaterium." Regardless of the term, it's a realm separate from our reality.

Humanity's scientific endeavors have long aimed to explore and exploit these other spaces, and the greatest achievement so far has been the development of interspace navigation. Think of it like the "space jump" technology you'd see in classic sci-fi novels. Ships enter this other dimension, ride its currents for a while, and then re-emerge, having traveled several light-years in what feels like just a few days.

Interspace navigation revolutionized humanity, propelling it from the age of horse-drawn carts into the realm of starships. Galactic distances that once seemed unfathomable became manageable. Yet, the journey was far from simple. The Immaterium, a realm of chaos and psychic energy, is filled with dangers and mysteries. Navigating through it was perilous—until the Astronomican came into existence.

The Astronomican, powered by the Emperor's unmatched psychic might, serves as a lighthouse amidst the unpredictable tides of the Immaterium. Anchored on Terra, its psychic glow pierces the Warp, guiding starships safely through its chaotic currents. But beyond its range, navigation becomes treacherous. Without its light, traveling through the Immaterium is akin to stumbling blindfolded across a storm-tossed sea, where every step could lead to disaster.

This limitation defines the reach of the empire. The regions illuminated by The Astromonican are the extent of the Imperial Corps' effective control. Anything beyond is wild and untamed. In remote areas under attack, the empire might deploy forces—if resources allow. But in regions so distant that even the emperor's will cannot extend, the outcome is inevitable. Those places are abandoned, left to their fate.

Technically, all planets in the galaxy fall under the emperor's domain, but the reality is far from ideal. Even within the tower's glow, the empire struggles to maintain order, let alone in worlds outside its light. To the empire's residents, Kayvaan's newly granted fiefdom was considered the frontier—wild, unprotected, and isolated.

"Sir, there's no need to worry," said an old man, trying to reassure Joe. "Your fiefdom hasn't seen a large-scale invasion by alien creatures in the past nine thousand years. It's likely to remain peaceful for the next nine thousand."

Kayvaan frowned. "Or it could be overrun tomorrow by something emerging from the depths of the universe. And the empire wouldn't lift a finger to save it."

The old man sighed. "I won't deny it. That's a possibility."

"I understand," Kayvaan said, staring at the letter of appointment on the table, its weight far heavier than the parchment it was written on.

Three days later, Kayvaan's confinement and surveillance were lifted. For the first time since his awakening, he stepped outside and felt the fresh, free air. Waiting at the monastery's door was Darius, his ever-cheerful companion. "Welcome back to the world!" Darius said with a grin. "Any plans for the near future? Never mind, let's discuss it in the car."

They climbed into an old black classic car, its engine wheezing like an asthmatic elder. It groaned to life and slowly carried them away from the monastery, leaving behind the scent of grass and trees. As they turned a corner, Kayvaan found himself in a starkly different world—a sprawling city of towering steel structures. 

"I'm surprised. Terra is really like this now. The monastery you were in before is one of the few places left with actual green space. The land here is so expensive that there's no other choice but to build up or out. And as the Empire gets stronger, Terra's value keeps climbing. Nobles from across the galaxy need offices in the Imperial capital. Wealthy people from everywhere are desperate to buy property here. That's why Terra has turned into one massive city.

"I read somewhere that Terra used to have a 'sea.' They said it was like a gigantic bathtub, endless to the eye, with salty water. Is that true?"

"Of course it's true. Are you saying there's no sea left on Terra?"

"Nope. According to books, the mountains have been flattened and the seas drained. But I've never seen mountains, rivers, or oceans myself. I've lived on Terra my whole life, and all I know is what you see now—a sprawling metropolis packed with people and buildings. Honestly, I'm tired of it. These days, only the wealthiest nobles still have their private green spaces or monasteries."

Kayvaan didn't want to dwell on the topic. He wasn't an environmentalist, and the state of the planet wasn't something he had the energy to care about. Right now, his focus was on more immediate matters. "So, where are we going now?"

"My place," Darius said, his tone casual. "You can stay there for now. The festival just ended, and finding a place to rent right now isn't easy. Do you have any plans for the near future?"