The night came and she didn't sleep. She couldn't. There was no way to 'power-off' an homunculus short of killing it. Her Core hummed, continually pumping mana through her veins and serving as a heart that didn't beat.

Homunculi were dead, or almost dead, creatures 'brought back' alive through magecraft; their bodies were rejuvenated, their veins aided with mana circuits and their heart's switched for a core that used mana to keep everything working—her skin, her lungs, her brain, everything ran on that mana. In the process of such a creation, however, the soul of the human vanished to whatever afterlife existed and the result would be an entirely different being housed in that new heart but using the mana-pumped brain to function as a human.

Simplified, the core was the power source and the thing that housed her memories—and thus herself—and the code and restrictions used to create her. While her brain that connected to it, and was kept functional by it, handled everything else.

All of these were basic things everyone knew, human or not, and understanding it led to her next thought.

'Something to hide it. . .'

Rose closed her eyes, sitting within that workshop as she felt the hum of her heart. Other homunculi would be able to hear it too if they strained their attention, and that had been how the Scrap Shop attendant had realized she was the same as him, it was something an homunculus could use to judge the Series of another and their condition. It was their signature.

Data floated in her mind. She was close to 83% charge and her brain revved up in thought. She shifted through the new knowledge of Magecraft or, more specifically, Core Control and building, she had gained.

In the end, everything clicked into place with the words 'Core Barrier,' something that was exactly how it sounded—a shield of mana that would surround her heart. Its main function kept another mage from tampering with a product but, built right, it also worked well to block the signatures an homunculus gave off.

And, to build such a thing, she would need to use and control a lot of mana at once—something she couldn't do with her current abilities and thus there came a need to rely on a Mana Orb and constantly replenish it. Rose thought hard, the decision was stringent based on her current situation, but a safety measure wasn't something she could neglect.

'No wonder she had no barrier. . .'

No wonder she had been able to break into Maria's core so easily. Lux was not someone who could afford to squander cores and he doubted there were any mages in the slums, if they existed besides him, that would waste their time trying to steal his homunculus. Maybe, as she brought up Maria's memory, he wasn't even skilled enough to make such a thing or hadn't learned to. He had failed to graduate from Alos's Mage Academy, after all

She took the useless gun and ripped the mana orb out of it. The whole thing, however, came crashing apart into scraps of metal.

". . ."

Had the man built this himself? She now wondered. She would have tried fixing it but she had no knowledge on the machinery branch of magecraft.

She gripped the orb in her right hand and then controlled her core to float out. It was odd staring at her own 'heart'—though that felt somewhat like the wrong word to use as she still had a heart—a crystallized ball of translucent blue that only differed from an orb in so far as the squirms of mana lines that floated within it, bundled up like a collection of wires.

She controlled the mana within the air and attached lines of them through her left hand, attaching partly to the orb and partly to the core. When all was set and down, she followed the instructions in her. Thankfully, she wasn't fixing or building a core, only adding to it, else she would have kicked herself for selling the terrible Constructor so fast.

Minutes of concentration and focus passed, an easy task for a non-human like her.

Mana seeped out from the orb and transferred to her core. Blue lines soon punctured up from the surface of the thing, stacking like wires upon a field and, soon, a thin film of mana covered the core as the orb disappeared in light.

She stared at the creation.

It looked like a spiked ball, really. A heavily clear, spiked ball with a swirling, even more transparent, glass surrounding it. Underneath that barrier, and what was essentially the spikes, was a maze that only she knew how to navigate and connect to the actual core, and that would also act as a type of funnel that kept the signature of her core, the hum, from reaching any other homunculus in full—keeping them from from knowing what she was.

She took the core back into her and data quickly floated in her mind. She was at 80% charge, her energy depleted at about 20% per day, and a low-grade orb could fill her to 100% from 0% before disappearing.

Just like that, the amount of days she had left was shaved down to 10. Two orbs every 5 days, one to keep her alive and one to keep the barrier in function. Provided the fact she didn't eat any food, which was already an inefficient way to charge. A regular 3 meals of a human might only give her half a day's worth of energy, if that.

She sighed.

Rose glanced at the two corpses on the floor and decided she would have to get rid of them if she wanted to keep staying here. She stood and proceeded to use the clothing in the bin behind her to cover the both of them, including the head of the man, before dragging them out to the dune-buggy. She went back inside and dug through the second bin, taking a metal scrap that seemed a good size, and bringing it out with her as well.

It was the dead of early morning. All was quiet and there were hardly any humans moving about in the slums. The task of making a Core Barrier had actually taken her all night but she didn't feel any more tired or weak. Of course, she was definitely not human.