Slave Walker
"It's okay, it's okay. Sonia, right? I wasn't trying to eavesdrop, but there's only one controller, so I heard everything. Don't look so apologetic—would you help me out a bit?"
Peko gave the side of the combat walker a light thunk, thunk. When she rested her palm against the machine, a mechanical synthesized voice rang out.
> Slave Walker — Opening hatch.
Slave Walker...? Not combat walker...? Are they the same thing...? I'm not sure...
With a soft hiss, a section of the thick armor plating slid open like an automatic door.
The armor had taken a suicide drone's detonation head-on and come away only slightly scorched—even at a glance, it looked extraordinarily durable.
"Don't just stand there staring—come over here and help me, will you? As you can see, I'm not exactly strong. I'd appreciate it."
"...Yes! Yes!"
Evening had long since slipped past, and the streets of Sky City were sinking into deep darkness.
"...Upsy-daisy!"
At Peko's request, Sonia stretched out her arms with everything she had and reached into the heavy Slave Walker's hatch.
In one hand, Peko carefully cradled a remote controller that looked fragile enough to snap. The black military uniform she wore seemed designed less for practical defense than to project a commander's dignity—closer to everyday dress than combat gear. Alone, she looked like she would struggle to pull Milli, who had collapsed inside the walker, free.
Sonia was a D-class hero, and though she too was dressed in an ordinary skirt and blouse, she possessed strength no ordinary person could match.
Even without her overwhelming bust providing any cushioning, lifting the combat walker's pilot—the being called Milli—and carefully setting her down on the ground was no trouble at all.
"I-Is this Milli? Peko...?"
"That's right. The Slave Walker's power source and bio-unit—and my little sister. You heard earlier, didn't you? That Milli is my sister. Well, on paper, at least, Sonia."
"Yes... I'm so glad she's okay..."
Before Peko had arrived on the scene, Sonia had exchanged various words with Milli.
This car-sized four-legged walking weapon was called a combat walker, or Slave Walker, and was said to be the latest weaponry operated by the Sky City military.
To compensate for vulnerabilities to hacking and EMP attacks, the walker was operated by having a human called a Slave Unit board it directly. An external pilot remotely controlled and commanded that unit.
A s-slave... you mean?
Originally, true to the name, as long as the intelligence requirements were met, slaves and violent criminals had been used as consumables—but the case of the sisters Peko and Milli was a little different.
Driven by their family's crushing poverty, the younger sister Milli had chosen the path of becoming a Slave Walker unit herself, and after grueling effort her older sister Peko had become a soldier and the manager—that is, the Master—of her little sister. It was a sad story.
(Th-This is glossy here too... This material is...)
The Milli that Sonia carefully extracted from the Slave Walker and laid down had the appearance of a human girl, but her body was closer to an elaborately crafted latex doll than a living being.
Matte black tights covered her from head to toe without a single gap. Even her face was completely sealed behind a breathing apparatus shaped like a gas mask, so not a patch of bare skin showed anywhere.
With practiced hands, Peko pulled down the gas mask covering Milli's face.
Dazzling white hair formed a vivid contrast against Peko's black military uniform. Revealed beneath the long hair was the face of a girl as beautiful and cute as a sleeping princess.
Their features were so alike that anyone would have called them sisters. The only difference was the color of Milli's eyes—a sapphire blue so vivid and artificial it looked like she was wearing contacts, depthless and unfathomable.
"So, what's your status? Can you move? Report immediately."
"My apologies, Master. Due to a system error caused by external impact, normal operational deployment is currently impossible."
"Hmm... Is that so? Got it."
(...?)
It was far too businesslike and cold to pass for a normal conversation between sisters.
In the way Peko carefully brushed the dust from Milli's body, a clear sense of caring for her little sister came through. Of course, whether that was caring for her as a precious core component of the Slave Walker, or caring for her pitiful little sister Milli, or both—it was impossible to say.
"Hmph... Well, she doesn't seem seriously injured on the surface, so we can just return to HQ. The problem is... how we get out of here from now on..."
Even Sonia, as oblivious as she was, could tell that Peko's face was practically screaming, I have a mountain of things to say, but I have no idea where to start explaining...
"...Uh... um... Sonia. You said you were a hero earlier, right?"
"Yes! Though I'm only D-class. I really never expected to get caught up in something this big. Heheh..."
"I heard you use a plasma pistol. Impressive. That's a weapon most smart heroes can't handle properly."
"Ah... ahaha... Thank you..."
Flustered by the sudden praise, Sonia absently twirled the ends of her blonde hair—which fell all the way to her waist—around her fingers.
"...So about that..."
This time, Peko's expression turned serious.
"...So about that... Have you thought of any plan for what to do from here, Sonia?"
"Well, since we saved people, shouldn't we just run full speed back the way we came? ...Ah..."
Until moments ago, the plan in Sonia's head had been very simple: escape the scene by pouring every ounce of her superior D-class hero stamina into it.
But right now, before her eyes, there were two people who could not move on their own. Simply abandoning the Slave Walker—a critical asset of the Sky City military—at the scene was not even an option.
As if she had been waiting for this, Peko calmly began explaining that she had another plan. Before that, she put the gas mask back on Milli's face and pulled the straps at the back tight to secure it firmly.
Small straps were also attached to the ends of the arms and legs of the tights Milli was wearing. Using those straps, Peko tightly bound Milli's arms and legs to her torso as if wrapping a mummy, rendering her unable to move.
Having finished all the restraints, Peko looked down at Milli lying on the ground like a doll and gave an order.
"Switch to inactive mode. Stand by."
"Yes, Master. Slave Unit switching to inactive mode. Standing by."
At Peko's command, Milli's faintly rising and falling chest rapidly settled, and all movement ceased—just like a machine whose power had been switched off.
"Alright, before the detailed explanation, let's take care of this first. Hey, can you grab the end of the legs for me?"
"Ah... Yes! Like this?"
"Yeah. Thanks. Hold it just like that for a second."
Though she still felt awkward about Peko casually referring to Milli as this, Sonia did as she was told and held Milli's legs.
With the skill of someone who had done this more than once or twice, Peko rolled Milli's body up and deftly stuffed her into a large black plastic bag she had pulled from her pocket.
"Ugh...! Physical strength really is the problem... This is hard... Alright, now I'll explain our plan, Sonia."
Peko tied the strings of the plastic bag containing Milli into a backpack form that could be worn on the back, then casually hoisted it onto her shoulders.
"Uh... uh... Yes... Please go ahead..."
Naturally, the candidate for the empty Slave Walker's new unit had been decided as a single person in Peko's mind from the very beginning.
"I'm asking you like this!"
"C-Can I really pilot a huge machine like that...?!"
Suddenly, Peko bowed her head deeply before Sonia. When a woman who looked older and higher-ranking than herself suddenly lowered her head, Sonia was flustered and did not know what to do. Of course, before that sudden gesture, Peko had added several despairing facts.
"I just received new field coordinates from headquarters. Drones are swarming the area again in massive numbers. See all these red dots on the controller? Every single one of them."
"It's a relief that most of the civilians successfully evacuated... but that also means our rescue priority is dead last."
"And you said you use a plasma pistol, Sonia. Operating a Slave Walker unit requires high intelligence stats above all else. If it's you... I'm sure you can do it!"
"I... I've never piloted anything like this even once... Can I... really do it?"
If she had just been a passing civilian, she might have refused Peko's absurd and dangerous proposal and gone her own way.
But at the starting point of this entire chain of cause and effect was that Slave Walker, which had thrown itself forward to save Sonia. That moral responsibility, combined with the desperate situation before her eyes, held Sonia's feet in place.