We found ourselves in a surprisingly empty courtyard, hemmed in by walls on all four sides. The only notable feature was a set of stairs, railings included, that disappeared into the ground below.

"That's the entrance," Margret said. "The place was originally an abandoned subway station."

We made our way down the stairs, through rusted, swinging doorways, until we found ourselves in a cavernous room. Despite the flaking paint on the wall, and burnt out lighting, (Margaret had quickly pulled out her own flashlight) the structure of the place seemed reassuringly sound. I quickly realized that the museum had been shut down long before any modern vehicles had been introduced, and that the space focused on one archaic object in particular: the train.

In fact, most of the exhibits we walked through were dominated by the things: huge, metal boxes that still gleaned dully with reflected light.

I walked over to one, poked my head through the open doorway. "What are we even looking for?" I asked, inspecting the garish interior, the hard plastic seats.

"Anything out of the ordinary - something that would seem out of place here. At the very least, access to the rest of the tunnels-" Suddenly, Margret shrieked, a sudden, chilling sound.

I bolted out of the train, rushing towards the noise. She'd wandered past me, into a further room, and I found her standing there, pointing at a massive protrusion in the room.

"What? What's wrong?" And then I paused, distracted, as I suddenly realized what the lumpy mass ahead of me was: the largest, most bulbous root I'd ever seen; thick and fat like a giant turnip in the ground.

"Sorry." Margaret shook her head. "I was startled."

"By what?" Her voice still sounded shaky.

"By them." She pointed, and I could see, beyond the roots, huddled a pair of large, hairy rats.

"Rats?" I almost laughed, thinking about the woman on the bus. "They're still hanging around, these days?" The rats did not seem overly startled by our presence. Margret's scream must have stunned them for a moment, but they were on the move again, and heading in our direction.

"Look," I pointed, as we sidestepped hurriedly out of the way. As they passed, I could see fragments of the trains in their mouths: shards of metal, wires. We glanced at each other for just a moment, before turning and following the strange pair.

The rats, still unbothered, led us to a new part of the museum - one that looked far shoodier. The trains were in bad disrepair, and roots and other organic protrusions emerged haphazardly from crumbling walls. But the strangest thing was that it seemed to be getting brighter, a dull yellow light that washed the shadows out.

Then we turned the corner, and saw the train, illuminated like it had been built yesterday. We came to a stop, both of us gaping. Ahead, the rats scurried forward, jumping through the open doors without hesitation. They joined an already seething mass of rats that were already on board.

"What is this?" Margret breathed. I simply stood there, uncomprehending. But then the train, quiet since our arrival, gave a quiet hiss - and the doors started to close.

Unthinking, I jumped forward, grasping at the sliding doors before they could shut completely. We tumbled inside, sending rats diving for cover, before the doors slid shut behind us, and the train started to move. The rats gave us a wide berth, each of them still clutching a piece of hardware in their hands, or mouths. We watched them as they watched us, the train gliding through the dark tunnels.

"What did you get me into?" I hissed. The slight rocking of the train was leaving me nauseous.

Margret didn't answer immediately. She looked away, towards the dark windows. We stood in silence for a few minutes as the train hurtled through space.

"Weser, I haven't been completely honest," she said eventually. "It wasn't old articles that led me here."

"Really? I'm shocked," I replied drily.

She smirked a little at that. "My grandmother had been an engineer who had worked on the bio-generator."

"What?"

"Yes. It was her journals I found, years ago, after her stuff had been passed down to me. She was old-fashioned, liked to write by hand. She wrote about how incredible it had been, how powerful she had felt..." Margret trailed off.

"But?"

"But something happened, I think - I don't know. Her writing was vague, on purpose, probably. But it was bad enough for them to hide the generator, leave it buried rather than use it again. Because it worked, after all. Saved the city, then the rest of the country. But I think there was they were worried about."

"Why are you telling me this now?" I asked. "I would have understood from the beginning, I think."

She laughed. "Look at us! We're in an ancient train surrounded by rats, going who-knows-where. I didn't think you'd follow if there was a chance of danger." Then quieter: "And I didn't want to tarnish this for you. You said it yourself - this thing is like the Holy Grail for you."

I leaned against the wall, sighed. "Well, it is what it is. Even if this thing ends up being some horrible contraption."

Margret chuckled. "True enough. I guess we'll wait and see." Then later: "Sorry about all this."

I smiled. "It's alright. I'm used to headaches."

Sometime later, the train slowed down to a shuddering stop. The doors slid open once again, and we followed the flow of rats as they exited. We traveled through a series of narrow tunnels before the station opened into a space many times more massive than the old museum. Despite the plant-life that engulfed the area, I could see elegant arches that curved high against the ceiling, cracking frescos that peeked through the roots. But the centerpiece of the massive hall, its source of light, and what the rats were flooding towards, was the huge, hulking machine that sat square-center on the floor. It did not resemble the pictures: sleek casings had been replaced with a patchwork of metals; displays and dashboards were dull and cracked. But as Margret and I huddled, hiding by the entrance. I pulled up one of the articles she'd sent me to compare. There was no doubt about it: we'd found the bio-generator.

"INITIALIZING SAMPLE." I nearly jumped out of my skin, whirling around to locate the sound of the droning voice.

*No, Weser - look!!!* Using the feeds to speak silently, she pointed towards the bio-generator, where a solitary rat was scurrying up its frame. Unlike the others, it had a stalk of some plant in its mouth, one end flowering. Focusing my feed identified it as a variety of orchid. We watched as the rat crawled up to one of the machine's orifices, dropping the sample in.

"PROCESSING," came the voice again, and the generator hummed and shook, it's makeshift parts vibrating. Moments later, a compartment slid open, which more rats scurried towards and retrieved the contents from.

*Those are seeds,* Margret pointed wildly.

*Forget that! It's an A.I.! - that's how it's capable of genetic design at that level. It must have redesigned these rats to be smarter, to assist it.*

We watched as rats scurried across the floor, bringing the machine new parts, new samples, heading into the darkness for replenishment.

"It really is incredible." Margret whispered aloud.

I agreed with her. But there was something horribly wrong about this stunted, warped machine, struggling to save a world that had started thriving long ago. Margret's grandmother, and the other engineers must have recognized the potential for uncontrolled disaster. But leaving it dead and buried hadn't been enough. It had come back to life, and balance had been pushed too far.

"It's time to put it to rest," I said.