He was immune to the effects of the virus, of course, but not to the creatures' aggression, so he'd given himself a few advantages.

He crept through the halls, his right hand clutching the gun. He'd never fired one before today, but they weren't very difficult to work out, and his marksmanship was superb due to the injections he'd designed and taken.

There was an office up ahead, so he ducked into it. The walkers were behaving beautifully, better than his wildest dreams, and he only hoped that he could reach a good observation point to take notes. Perhaps later, if he was lucky, he'd get to dissect one.

There was a noise, and he spun around, gun at the ready. The office wasn't as empty as he'd thought.

Ambrose Mengele sat up. He'd been injured, the boy could see, but he had managed to crawl away. "Are you going to kill me?"

The boy relaxed somewhat. He appeared to weigh this against itself and his other options.

"No," he finally decided. He looked over Mengele, his eyes tracing every injury. The man wouldn't live without medical attention, and, thanks to the virus, he wouldn't be getting any. "I've already done that."

It was true, the boy, though calling him a boy now was a bit of a stretch, reflected. He'd used the virus, which had used the unvaccinated residents of the facility. The mutants had dealt the blows, but he had used them the same way a murderer uses a knife, and to a similar end.

"What have you done?" The tones were smooth and deep and soft, as always, but for the first time they held a hint of uncertainty.

The boy checked the hallway. It was clear for now. "Only what you wanted me to do," he answered indifferently. It struck him how low his own voice sounded, how like the man's.

Mengele laughed a grating, hacking cough of a laugh. "You're making a mistake. You have no idea what it's like out there. The world's ended. Nuclear wastelands filled with nothing but ash… drowned and buried islands… mutated monsters roaming the earth… Humanity has destroyed itself… need to start again… I just wanted… a new order… a new world… so we could fix things." Mengle trembled with exertion, sweat glistening on his brow.

"You told me to build a weapon," said the boy, examining his gun. He didn't know how to refill the ammunition, and he suspected he was running out of shots. "You taught me everything I needed to know to do this." They both knew he wasn't talking about the textbooks.

Mengele gurgled. He didn't have long, and he knew it. "What was the point… of all this? What were you… trying to… accomplish?"

The boy pulled back the stock on his weapon, and one of the precious bullets slid out. Evidently, that was not how one refilled the ammunition. He pocketed it, against the chance he would figure it out later. "I haven't got a name. I haven't got an identity. That means all this is your legacy, your title."

"No," Mengele breathed. "I'm nothing like you."

"No," agreed the boy. "You're worse. I know what I am." He examined the gun once more. "But you're right. You're not me; you're weak. If the world outside is as broken as you say it is, I will be the one to unify it. Not you." The boy knew he wasn't being arrogant. It was a simple scientific assessment of ability.

There was nothing further from Ambrose. Perhaps he had died. The boy decided that he would simply have to find a new gun from somewhere, with new bullets in it. He peered out into the hallway.

There was a wheeze from behind him. "You won't… get far… you haven't even got… a name…"

"I do now," he said without turning. "I am your legacy."

And so he was. In a way, he supposed he was grateful. But he intended to go so much further than his progenitor.

What would he call himself? He owed Ambrose homage, nothing more.

Paul he decided. It fit better than most names, and just as well as any other.

He wasn't sure if Ambrose was even still conscious, but he said it anyways.

"I am Paul Ambrose Mengele. And I am more powerful than you."