Astrid had arrived on Earth in the year 1602, a moment forever etched into his memory. His starship, damaged during a journey across the cosmos, had crash-landed in the dense forests of what was now modern-day Korea. The sky had been ablaze with light as he descended, but upon impact, the world went dark, leaving him stranded in an alien land with no way to return.

In the following years, he had watched civilizations rise and fall, adapting to each era with the seamless ease granted by his advanced intellect and ageless appearance. By the time Seoul had grown into the bustling metropolis it was today, Astrid had mastered the art of blending in, assuming the role of Dr. Kim, a reclusive yet brilliant university professor. 

Astrid’s abilities were as extraordinary as his origins. He possessed a heightened intellect, far surpassing any human's. His physical capabilities were equally remarkable—telekinesis, teleportation, and an almost immortal body that could heal from any injury. These powers, which had once seemed like blessings, had become the chains that bound him to a life of solitude and secrecy.

Despite the centuries that had passed, Astrid remained an enigma to the few who knew him. He was a solitary figure who shunned close relationships, wary of the risk of exposure. The few colleagues and students who interacted with him often remarked on his brilliance, but even they sensed the invisible barrier he maintained around his personal life. In the rare moments when he allowed himself to reflect, he realized he had become a shadow, drifting through time with no real anchor to the world.

His life, as it stood, was a carefully orchestrated facade. He resided in a modest apartment filled with books and artifacts from every era he had lived through, each piece a silent testament to his long, solitary journey. His daily routine was methodical and predictable—lectures in the morning, research in the afternoon, and long, lonely nights spent gazing at the stars.

Astrid's latest research project, a study of quantum mechanics and its applications to theoretical physics, was both a testament to his intellect and a means to occupy his restless mind. Yet, even the most complex equations could not distract him from the gnawing loneliness that had settled deep in his soul.

The flashbacks came unbidden as he sat in his dimly lit study, fingers tracing the outline of an ancient scroll from the Joseon Dynasty. He remembered the faces of those he had encountered through the centuries, fleeting acquaintances who had come and gone, their lives mere blips in the vast expanse of his existence. Each interaction had been a lesson in restraint, a reminder of the consequences of forming bonds that would inevitably be broken by time.

In the quiet of his study, surrounded by relics of a past that no one else could understand, Astrid allowed himself a rare moment of vulnerability. He let his thoughts drift to the planet he once called home, to the family and friends he had left behind, and to the possibility that he might never see them again. 

The hum of the city outside was a stark contrast to the silence within, a reminder of the world he was a part of yet forever separate from. Astrid closed his eyes, shutting out the noise, and for a moment, he was just a man lost in memories, a silent star in the endless expanse of the universe.

As the night deepened, Astrid returned his gaze to the window, to the familiar constellation that had become his nightly companion. He knew his time on Earth was finite, that the day would come when he would have to leave behind the life he had painstakingly constructed. Until then, he would continue to play his part, the silent guardian of secrets that stretched across time and space.

But fate, as he would soon discover, had other plans. In the very city where he had learned to hide in plain sight, a chance encounter was about to set in motion a series of events that would change everything. For Astrid Kim, the silent star, was on the brink of a collision with destiny.