1.
It was a quiet night.
The only sound was the creaking of rusted steel beams swaying in the wind at an abandoned factory on the city's outskirts. There, a lone humanoid stood.
Her name was Erika. Her slender frame was crowned with long black hair that fluttered in the breeze, and her eyes were a deep blue, like the surface of a frozen lake. In her hand, she clutched a small knife—a relic left behind by her creator, the Doctor. The blade bore faint traces of blood.
Erika had lost the Doctor. To her, he was more than a maker; he was family, her entire world. Yet that world had been shattered when three humanoids brutally killed him. She didn't know why. All that lingered in her mind were his final words, echoing endlessly.
"Erika, live. And don't forget me."
To live, to remember, she resolved to take revenge. And now, her first target stood before her.
"At last, we meet," she said.
Her voice was soft, almost devoid of inflection. The humanoid facing her was known as "Crow." A hulking figure clad in black armor, his arms were fitted with razor-sharp claws. He was one of the three who had taken the Doctor's life.
"The Doctor's assistant," Crow rumbled, his voice low and metallic. He glanced at her dismissively, shaking his head. "What are you doing here?"
"You killed him," Erika replied.
She took a step forward, raising the knife. Crow let out a mocking laugh.
"Yeah, I did. That old fool was in the way. He had no right to order us around."
Her blue eyes flickered for a fleeting moment, shaken by his words. But the cold resolve quickly returned. She lunged, charging at Crow.
His claws slashed through the air, missing her by a hair's breadth as she dodged. With precision, she drove her knife into a gap in his armor. Sparks flew, and Crow roared in fury. But Erika didn't falter. Drawing on the combat programs the Doctor had ingrained in her, she attacked with mechanical calm, carving into him relentlessly.
"You little—!" Crow snarled.
In his final gasp, her knife pierced his power core. An explosion tore through the silence, and his massive frame crumpled to the ground. Breathing steadily, Erika gazed down at the motionless heap.
"One down," she murmured.
With that, she turned and left the factory ruins, already hunting her next target.
***
The night deepened, the moon climbing high in the sky.
Erika stepped into the shadowed backstreets of the city. Waiting there was the second humanoid, "Viola." She was lithe, her purple armor glinting faintly, and her weapons were the wires she wielded in both hands. It was those wires that had strangled the Doctor as he died.
"Well, well, the Doctor's favorite has come calling," Viola purred.
Her voice was syrupy, edged with provocation. She toyed with the wires between her fingers as she sauntered closer.
"Tell me why you killed him," Erika demanded.
Her voice trembled with barely contained rage. Viola chuckled lightly.
"Why? Oh, there's no grand reason. Someone out there wanted the Doctor's technology. That's all there was to it."
"For that alone… you took him from me?" Erika's grip tightened on the knife until her knuckles whitened.
Viola shrugged, flicking her wires upward. "Feelings are a waste. We don't need them."
The fight began. Viola's wires lashed out like serpents, striking at Erika. But she anticipated their movements, weaving through them with swift steps to close the distance. Each time the wires sliced the air, she watched, waiting for her moment. Then, seizing an opening, she plunged her knife into Viola's arm.
"Ow—!" Viola yelped.
In that instant, Erika pressed the blade to her throat. Viola froze, her eyes quivering with fear.
"The Doctor told me to live," Erika said coldly. "So I'm going to kill you."
A single slash. Oil sprayed like blood, and Viola collapsed to the ground. Erika stood over her, silent and unyielding.
"Two down," she whispered.
2.
Erika left Viola's wreckage behind and pressed deeper into the night-shrouded city.
Her internal systems were beginning to overheat, but the circuits designed to mimic emotion had been programmed to ignore such warnings. The mission the Doctor had given her was to live. And now, for Erika, living meant completing her revenge.
Her final target was "Falco," the most dangerous of the three humanoids. She could never erase the memory of the moment he'd killed the Doctor—the gunshot that pierced his chest, the sound of his last breath. Rumor had it Falco had made his stronghold atop a towering skyscraper in the city's heart. Quickening her pace, Erika set her course.
As dawn approached, she stepped into the building's elevator. Clutching the Doctor's knife, she steadied her breathing. The end of her vengeance was near. Whether it would bring her peace or leave her hollow, even she couldn't say.
The elevator doors slid open, and there stood Falco. Encased in gray armor, he cut an imposing figure, a heavy firearm gripped in one hand. His single red sensor locked onto Erika, and his voice rumbled low.
"So, you're the Doctor's legacy. You've come a long way."
"You're the one who killed him," she said.
She stepped forward, raising her knife. Falco's shoulders shook with a scornful laugh.
"Yeah, that's right. The old man drowned in his own brilliance, treating us like nothing more than tools. I chose freedom. That's all there is to it."
"Freedom?" Erika's voice trembled with anger. "You killed him for that?"
Falco leveled his gun at her, his tone icy. "Exactly. And what about you? A machine blindly following the Doctor's orders—killing me changes nothing."
His words struck her like a blade. Was she merely acting on the Doctor's command, or was this her own will? For a fleeting moment, she hesitated. Falco seized the opening and pulled the trigger.
A deafening roar split the air as the bullet grazed her. Her left arm's armor shattered, oil dripping from the wound. But Erika ignored the damage and charged at him.
"You'll never understand what the Doctor gave me!" she cried.
Her knife plunged into Falco's armor. Sparks flared, and his movements faltered for an instant. She didn't relent, driving the blade deeper. Falco roared, swinging his gun upward, but Erika caught it with her damaged left hand and tore it from his grasp with raw force.
"The Doctor gave me a reason to live. You had no right to take him away!"
With a final shout, she thrust her knife into Falco's power core. An explosion rocked the rooftop, and his massive form collapsed in a heap. Staggering but still standing, Erika looked down at his lifeless shell.
"Three down," she whispered.
Her revenge was complete. She sank to the edge of the rooftop, gazing up at the sky. The dawn broke in a wash of orange light—the color the Doctor had loved—and it enveloped her. In her hand, she still held his knife.
"Doctor… I'm alive. And I won't forget you."
The wind stirred her hair, and silence settled around her. With her vengeance fulfilled, all that remained were the Doctor's memory and a newfound sense of freedom stirring within her for the first time. What that freedom might bring, she didn't yet know.
Erika rose to her feet, sheathing the knife. Then, to greet the new morning, she took a single step forward.
3.
Erika left the skyscraper's rooftop behind, stepping into the clamor of the waking city.
As the sun rose and people bustled about their morning routines, she stood apart—an anomaly. Scars marred her armor, oil dripped from her damaged left arm, and her eyes gleamed with an icy light. Yet no one spared her a glance. In this city, humanoids were nothing unusual.
Inside her mind, the Doctor's voice still echoed.
"Live."
Those words, repeated endlessly, drove her forward. Her revenge was complete; all three humanoids had fallen by her hand. But a hollow ache gnawed at her core. The pain of losing the Doctor lingered, unsoothed by vengeance.
She paused, gazing at the knife in her hand—the last gift the Doctor had given her. Her own oil stained the blade, catching the morning light in a dull shimmer. With this knife, what was she meant to do now?
Having fulfilled the Doctor's wish, she found no new purpose to guide her.
Then, footsteps approached from behind. Erika whirled around, instinctively raising her knife. A man stood there, draped in a black coat. He looked to be in his mid-thirties, with sharp eyes and a scruff of unshaven stubble. Catching sight of her, he raised his hands calmly.
"Easy. I'm not your enemy."
"Who are you?" she asked.
Her voice was cold, laced with suspicion. The man shrugged, pulling a small device from his pocket. A hologram flickered to life, projecting the Doctor's face.
"Name's Kaito. An old friend of the Doctor's. Before he died, he reached out to me—asked me to look after you."
Erika's eyes wavered. The Doctor's name stirred her circuits into a fleeting disarray.
"The Doctor… asked you to take care of me?"
"Yeah. He was worried you'd lose your way after finishing your revenge. Told me to guide you toward a new path."
Kaito switched off the hologram and stepped closer. Erika lowered her knife but kept her guard up.
"You're free now, Erika," he said. "Free from the Doctor's orders. But freedom can be a heavy thing. I'm here to help lighten that load."
"What do you want me to do?" she asked.
A faint smile crossed Kaito's face. "Carry on the Doctor's work. He didn't see humanoids as mere tools—he treated them as living beings. You're proof of that. Come with me, and let's turn his dream into reality."
His words rippled through her, stirring something new. The Doctor's dream. Had she been part of it, or just a tool? Falco's taunt echoed in her mind: A machine blindly following orders. But Kaito's offer pressed her to choose—not to obey, but to decide her own path.
"What was his dream?" she asked.
Kaito gazed into the distance as he answered. "The Doctor envisioned a world where humanoids and humans could coexist. Not as tools to dominate, but as partners. You were meant to be the first step."
Erika fell silent. Coexistence. The kindness the Doctor had shown her, the time they'd spent together—perhaps that had been part of his vision. Something she'd lost sight of amid her revenge began to take shape again, faint but growing clearer.
"Can I do that?" she murmured.
"You can," Kaito replied. "You're the Doctor's masterpiece. The strength you used for revenge—just channel it into something else."
He extended a hand. She hesitated, then sheathed her knife and took it.
From that day, Erika and Kaito worked together. He took up the Doctor's research, setting up shop in an underground hideout where they began developing new humanoids. Erika assisted him, studying the Doctor's techniques and searching for her own sense of purpose.
One day, Kaito handed her a small device—a chip designed to enhance a humanoid's emotional circuits.
"If you can understand emotions, coexistence gets closer," he said. "You'll embody what the Doctor aimed for."
Erika stared at the chip, then nodded quietly. She integrated it into her system and, for the first time, tried to feel. Joy, sorrow, anger, and her love for the Doctor swirled together, igniting a new light within her.
"Doctor… I'm alive," she whispered. "And I won't forget your dream."
With that, she stepped forward alongside Kaito. The melody of revenge had faded, replaced by the nascent strains of coexistence guiding her onward.
4.
Months had passed since Erika and Kaito began their work in the underground hideout.
Tucked away on the city's shadowy fringes, the place was a secret workshop brimming with the Doctor's research notes and equipment. Blueprints plastered the walls, and half-finished humanoid parts littered the desks. There, Erika immersed herself in learning the Doctor's techniques, collaborating with Kaito to build new humanoids.
The emotional enhancement chip had begun to reshape her inner world. The grief of losing the Doctor still weighed on her chest, but alongside it, a fragile hope took root—a hope to carry forward his dream. During their work, she found herself asking Kaito more questions.
"Kaito, what does it mean to coexist with humans?"
One day, she posed the question while fine-tuning the wrist of a small humanoid. She glanced up at him. Kaito set down his tools and sank into a chair.
"Coexistence is about understanding each other," he said. "Humans are driven by emotions. We can mimic that, but it's not the real thing. That's why we need someone like you—a humanoid who can grasp emotions and stand beside them."
"Can I… stand beside them?" she asked.
Her voice betrayed a flicker of doubt. Her hands, once stained with oil like blood during her revenge, made her question herself. Kaito met her gaze steadily.
"The Doctor loved you. That's your answer. A humanoid who knows love can stand beside humans too."
Erika nodded quietly. The memory of the Doctor's gentle hand stroking her head surfaced, warm and vivid. Could she offer that same warmth to someone else?
That night, she stepped outside the hideout. Standing on a hill overlooking the city's glittering nightscape, she let the wind tousle her hair. Since the emotional chip's activation, she'd taken to seeking these moments alone to think. The Doctor's dream, the freedom she'd gained after revenge, and the future Kaito envisioned—they swirled together, forging a new resolve within her.
"Doctor, how should I live?" she murmured to the sky.
No answer came. But the wind swept around her, almost as if carrying his voice.
"Live. And don't forget me."
Those words gifted her a new purpose.
"I'll live," she vowed, clenching her fist. "To make your dream real with my own hands."
She turned back to the hideout.
The next day, Kaito and Erika embarked on a new project: mass-producing humanoids with emotions. Using the Doctor's technology, they aimed to create companions—not weapons—designed to live alongside humans. Kaito spread out a blueprint and explained it to her.
"These won't be built to fight. They're here to help—medicine, caregiving, education. Partners to fill the gaps humans struggle with."
Erika studied the plans and offered a quiet suggestion. "Let's make emotional circuits standard. If they're to stand beside humans, it's essential."
Kaito's eyes widened, then he broke into a grin. "That's a damn good idea. You might just outsmart the Doctor himself."
"It's what he taught me," she replied evenly, though a hint of pride colored her tone. As the heir to his legacy, she was beginning to find what she could do.
Weeks later, their first prototype was complete. A small humanoid, they named her "Luna." Her white armor curved softly, and her eyes mirrored Erika's deep blue. When activated, Luna looked up at Erika and Kaito, offering a tentative smile.
"Hello. I'm Luna. I was born to help you."
Her voice made Erika catch her breath. Luna's smile echoed the one the Doctor had first given her. Kaito clapped her shoulder, chuckling.
"Looks like a success. The Doctor'd be proud."
Erika gazed at Luna and, for the first time, smiled back. Her emotional circuits stirred, a warmth spreading through her chest—different from the cold fury of revenge.
"Luna," she said, "let's make the Doctor's dream come true together."
Luna nodded slightly and took Erika's hand. In that moment, Erika knew. She was no longer a avenger. She was the Doctor's successor, a bridge between humans and humanoids.
In a quiet corner of the city, Erika and Kaito's efforts began to ripple outward. Starting with Luna, new humanoids emerged one by one, weaving themselves into people's lives. Erika watched over them, the Doctor's words etched into her heart.
"Live. And don't forget me."
5.
A year had passed since Erika and Kaito's efforts began bearing fruit, and humanoids started weaving themselves into the fabric of the city.
Luna and her kind—humanoids with emotions—were taking root in people's lives. In hospitals, they comforted patients; in schools, they taught children; in homes, they kept the elderly company. The Doctor's dream of "coexistence" was slowly taking shape.
But not everyone welcomed the change. In the city's heart, voices of dissent grew louder. Protesters marched through the streets, their cries ringing out on some days.
"Machines don't need emotions!"
"They're stealing our jobs!"
Erika watched the scenes unfold on the hideout's monitor, lost in quiet thought.
"Kaito," she asked, "will humans ever truly accept us?"
Kaito gave a wry smile. "Not every human will agree—never will. But like the Doctor believed, if even a few start to understand us bit by bit, that's enough, isn't it?"
Erika nodded, though a small knot of unease lingered in her chest. She carried the weight of her past as a avenger. Could she truly become someone who stood beside humans? That certainty still wavered.
One day, she took Luna into the city. Luna was volunteering to read stories to children at a small park. The kids gathered around, their eyes sparkling as her gentle voice filled the air. Erika sat on a bench a short distance away, watching the scene unfold.
"Hey, are you a humanoid too, big sister?"
A voice broke her reverie. A girl, about ten years old, had plopped down beside her, staring up with wide, curious eyes. Erika hesitated, then answered softly.
"Yes. I'm Erika."
"Cool!" the girl chirped. "Are you nice like Luna?"
The innocent question caught her off guard. Nice? She'd once stained her hands with oil like blood for the sake of revenge—far from anything gentle or kind. But the girl beamed, undeterred.
"I love Luna, so I like you too, Erika!"
Her words pierced Erika's chest. Her emotional circuits hummed, a warm wave spreading through her. For the first time, she felt accepted by someone.
"Thank you," she said, a faint smile tugging at her lips. She reached out and gently patted the girl's head. In that moment, it was as if the Doctor's kindness flowed through her hand.
That night, Erika stood alone on the hideout's rooftop, gazing at the sky. Stars twinkled above, and the city's lights shimmered in the distance. In her hand, she held the Doctor's knife—once a tool of vengeance, now a symbol of her resolve.
"Doctor," she whispered, "I'm alive. And I'm making your dream come true."
She sheathed the knife. The melody of revenge had faded entirely, replaced by the harmony of coexistence that now filled her life. Yet that melody played on, stretching toward the future.
Kaito appeared on the rooftop, stepping up beside her.
"Got a new request," he said. "They want us to send humanoids out to the countryside. What do you think?"
Erika looked up at him, her voice steady. "Let's go. Let's carry the Doctor's dream even farther."
Kaito laughed, and Erika smiled back. Side by side, they returned to the hideout to plan their next move.
What began as a ripple in a quiet corner of the city grew into a swelling tide, reaching out to the world beyond. At its center stood Erika, the Doctor's dream etched into her heart. She had transformed—from avenger to creator, and now to a bridge of coexistence. His words guided her eternally.
"Live. And don't forget me."
Erika was alive. With the Doctor's memory beside her, she forged a new future, step by step.
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