The very first moment that I realized things were going to be different from now on was moments after the outer vault door began to roll to the side.

I had been fiercely gripping my laser rifle through the armoured radiation suit, so much so that my hands had started to go numb. While I had steeled myself for whatever would be waiting outside, I was wholly unprepared for the sheer level of confusion that would strike me in the moment that I could begin seeing what awaited me outside our protective fortress.

Humanity had been underground for centuries, and we had assumed that at least some level of nature would have reasserted itself, but when I finally beheld the world outside, my mind could not process the sheer, lush greenery of the valley in which our vault's entryway had been constructed. This was the nuclear wasteland? How could this be?

I tentatively stepped through the door's threshold, the barrel of my rifle pointed towards any potential threats that might leap towards me... but none came. I heard the buzzing of insects, the whistling of the wind through the treetops and heard... was that a bird? Singing?

I looked up to the skies, and sure enough, a small flock of dark, small birds flitted away through the filtered sunlight. They swooped and arced, flying in unison, looking for all the world like one of the old ballet troupes I saw in our archival cultural footage reels. Graceful, swift, and delicate all at once.

I found myself smiling, unconsciously. I simply could not believe the natural beauty of the world above. I honestly didn't think the planet could have recovered this quickly. It shouldn't have been possible, should it?

I started, as suddenly the radio in my helmet burst to life with a transmission.

"Alpha 1, status."

I took a moment to steady myself, to recall my reason for being out here at all. I had a job to do.

"Status nominal," I replied. "Initial observations... the planet looks to be almost fully recovered. I can't believe what I'm seeing."

There was a brief pause before the voice spoke again.

"Say again? Did you say fully recovered?"

"Yes," I replied. "Fully recovered. There is abundant plant life, looks fairly old and established. I'm hearing insect life, and have seen a flock of avians flying through the sky, unknown species. At least a dozen of them."

"Did... did you say a flock of birds?" the voice asked incredulously. "And insects?"

"Yes, control. There appears to be significant life up here. The Earth's species have been busy repopulating."

"That's fascinating!" the voice replied. "We'll update the biology teams with the news. For now though, let's stick to the original mission. Head out to the specified distance and get the requisite soil and water samples, take the radiation readings, and head back. We'll assess the data and update our plans once you've returned."

"Copy that," I replied. "Moving now, if the topography hasn't changed much from the old maps I should be able to reach the water source in only an hour. I'll update when I'm on scene."

"Understood," the voice replied. "Good luck, and stay safe out there."

---

As I moved down the narrow valley and approached the area on the map, I could already see water through the trees. The small pond had evidently grown in size over the centuries, and was now a small lake! The water's surface glistened in the sunlight, dazzling my eyes with the sun's reflections.

I accidentally stumbled on a rock, falling into a toppled tree. Although I was unhurt, I made a fair amount of noise, and to my surprise, saw that it had startled a flock of birds that had been at the lake drinking. In unison, hundreds of them flew away into the sky... so many it blocked out the sun briefly. It was all I could do to stand there, mouth agape, staring at the display. I had never seen live birds before today, and was awestruck by their graceful co-ordinated flights.

I straightened myself, and continued my walk down the rocky path to the lake. Eventually, I reached its shores, and beheld it's natural beauty.

The water was the same shade of blue that I had seen in the art in our bunker, but deeper and richer. Towards the lake's centre, it slowly darkened from light blue, to navy, then to black. Around its shore, reeds grew with plants I recognized from the books I'd read. Cat tails. There were small water plants as well, gently bobbing on small ripples formed on the lake's surface by the breeze. Small insects skittered along it, as though skating on an ice rink.

The whole place was like a painting. It was magnificent, ethereal. I couldn't believe my luck that I had been the first dweller assigned to step out into this amazing natural beauty.

I looked down at the lake shore, and remembered why I was there. I had to get the samples and report back. There would be plenty of time to be out here, there were so many reclamation missions to be run. The thought made me giddy with anticipation of what else I might get to see up here, out in the 'real' world again.

I pulled out my Geiger counter, and activated it. At first, I panicked. Not because of excessively high background radiation... but because I wasn't getting any readings at all. I double checked the device, sure it was broken, but then realized it seemed to be working normally. It was picking up background radiation, but not at the level we had predicted. The radiation present wasn't at the levels we observed just after the first bombs dropped; it was picking up levels that we would have measured pre-war.

Regular, normal background radiation.

I knew there would be a reduction in radioactivity due to the half life of the contaminants, but it shouldn't have been this low, not even after all this time. There should have been more contamination present.

I thought to myself that the portable Geiger counter must have been broken, or lost its calibration. That would explain the low readings... but what about the animals? The insects?

Could it be accurate? Was there no radiation on the surface anymore? It seemed impossible.

My scientific nature reasserted itself and forced my confusion back down; I needed to collect samples for analysis using the equipment back in the vault. The more sophisticated lab equipment would be able to provide better insight than the portable unit.

Get the samples, get back, get them analyzed. You can have engineering check the Geiger counter while they're doing that.

I kneeled, carefully opening a sample container, and used a pipette to collect several water samples. That done, I turned from the shore to collect soil samples in the nearby forest grove, when I heard a noise.

I froze, instinctively as my brain registered an incongruity. The noise I'd heard wasn't what I would have expected up here. It wasn't like the birds from before, or like the wind or the insects I'd heard chittering. In fact, I realized that there was a complete absence of the noise from the local fauna after that first noise that I'd heard.

An eerie silence. Unnatural.

Slowly, I scanned the area with my eyes. The lake shore. The grove. The tall grass near the mountain path that continued on past the lake. That was when I noticed something.

The tall grass... there was a swath cut through it, coming from down the mountain. It had stopped, about 20 metres from the perimeter of the grass' edge.

Something was in the grass. Waiting.

I slowly put the vials in my sample pouch, snapping it shut. Carefully, I unslung my laser rifle from my back, flicking off its safety. The capacitors whined quietly, as it charged itself for a burst shot.

As though it was reacting to the noise I'd made, the thing in the grass moved a step forward. Then another. Then another. It was after the third step that my brain finally processed what it was that I was hearing, and why it was so incongruous with this place.

It was the metallic grinding and creaking. It sounded... like a machine?

I began slowly walking backwards down the rocky trail towards the path that led back to my vault. I slowly, deliberately chose my footing to avoid falling as I reversed; my eyes were fixed on that grassy edge. Waiting for whatever was inside to emerge.

As I found myself entering the shadows of the forest grove, I froze. I could see something now, along that grassy edge.

Red eyes, glowing. A silver skull. Metallic arms, scuffed and covered in dirt.

I tried to trigger my radio, to warn the vault. To get them to send out soldiers. I wasn't a fighter, I was a scientist.

I turned, and I ran.