“Tabby?! Where are you? We are out of time!” Evan searched desperately for his sister through the base barracks. The flimsy metal building was cold, so very cold. The shelter would be sealing any minute now, and they would be trapped.

“I’m cold, Evie,” came a small voice from under the bunks he’d just walked past. Evan slid to his knees and looked underneath. His six-year-old sister was bundled up in a nest of blankets.

“Why are you hiding there? We should be underground already!” he scolded as he pulled her out. “We need to run!”

Of course, their running speed was limited to the trotting speed that a small child could manage. Evan was only fourteen, not big enough to just carry her and run.

“Is Momma mad at me?” asked the little girl. “I don’t like it down there, it doesn’t have any windows.”

“Momma and Dadda both are worried. I wasn’t supposed to come out and look for you.”

Once the doors were closed, they were supposed to stay closed. The timer was set, the doors were going to close and wouldn’t open again until after the blizzard passed. No one outside of the shelter would be able to survive. Rumors had gone around that the storm would last months, if not years.

The shelter entrance came into view. Evan could see the massive door slowly starting to swing closed. The jerkface guard that had laughed at him when he left to find Tabby was arguing with his parents, but the door was closing anyway.

“WAIT!” shouted Evan. He picked up Tabby and moved faster. He couldn’t carry her for long, but it was still faster than waiting for her. “I’ve found her! WAIT!!!”

The guard was pretending not to hear him, but both of his parents saw them, and started screaming and pointing. The guard had a sour look on his face when he punched in a command on his keyboard. The door stopped moving.

Evan ran as if the door hadn’t stopped. He didn’t trust that guard not to start it again before he got there. In fact, even as he slid in the entrance, gasping and sweaty in the frigid air, the door started moving on its hinges once again.

“Tabby! You had us so worried!” said Evan’s mother, even as his father grabbed him into a tight hug.

“I’m sorry, Momma,” said a tearful Tabby.

“It’s okay, everything is going to be okay,” she said as she hugged her close, even as the massive steel door boomed shut behind them.

“So we’re going to start sending ships out from the Outpost?” asked Sakura over radio. She wasn’t in the room. In fact, she’d gone out of the HQ zone a few days ago while Agrippa tried to establish communications with the interstellar probe. So far, all attempts to speak with it had been ignored. The probe kept repeating itself, over and over.

“It’s time,” I said. “You have your drones ready for the new bases?”

“Sure! My starter packs can move as soon as you say the word. We’ll have four new bases starting within a week or two. The furthest is 31,809 kilometers away, the closest is 5,212 kilometers.”

“How long until they are productive?” I asked, knowing the answer but wanting to be reassured before approving. This was the biggest move we’d made since getting our own location self-sufficient.

“With regular materials shipments from Ganymed, initial factory construction will happen as quickly as we can dig in. As these are primarily military outposts, and don’t require immediate self-sufficiency, they will be able to house assault drones and produce their own ammunition in approximately seventeen days of landing. They will produce their own drones in eight months, and be self-sufficient in eleven.”

“How many bases will be started by the end of eleven months?”

“All of them.”

“All sixty-three that Agrippa proposed?”

“Yes. The last bases will be ready in thirteen months.”

“How…” Right, self-replication and exponential growth. Sometimes my own human-scale thought processes interfered with basic math. We had hit 100,000 drones a few weeks ago, and would be doubling that within the month.

“Start it now. Are we still overflowing with basic materials?”

“We are. The new bases will help with that, but especially nickel-iron and steel, we have tens of thousands of tons sitting in storage. I estimate the new bases will account for fourteen percent of the excess, but by the time they are complete, we will be at 118% of storage capacity.”

“118% of today’s capacity, or 118% of the capacity we will have?”

“The second one,” she confirmed.

“And our military drone production?”

“We are filling hangars as fast as we build them. I brought two more online today. By the time the hangars are ready on the first military base, I anticipate we will have sufficient production to fill them on the first day.”

“Agrippa?” I called, patching him into the radio conversation.

“Yes?”

“How goes the communication attempts?”

“Poorly. I believe the probe is broken. I’ve sent out a few Wasps to try and search for it, but space is… really big.”

“Ha,” laughed Zia. “Understatement of the year. I hope you don’t mind my joining the meeting of the minds?”

“Not at all,” I said, although I did, sort of.

“If you would like some assistance, I could lend some of my talents towards helping pin down the best search locations. We know the trajectory the probe used to leave the solar system. If the probe got turned around, it would likely take a similar path back in. Since we know the exact location of its exit, relative to Earth, and we know exactly when it left, then its just orbital mechanics.”

“Oh! And we can calculate when and where it would return if it followed the same path to come back!” said Sakura excitedly.

“Just so,” said Zia warmly. “I’m glad to see you know how to use that mind of yours for more than building things!”

“I can use it for much more than that! Have I shown you my bungee jumping setup in the old entrance tunnel?”

“It’s more of a slingshot setup,” said Agrippa. “I’m still trying to determine if it has useful training purposes for our Guardian drones.”

“You’re allowed to admit that it was fun,” said Sakura.

“Wait a minute, is this how you damaged your original android body? Is this why you switched to the Mark-III before I was done testing the prototype?” I asked suspiciously.

“Well, I may have miscalibrated the slingshot, so the bungee jerked me back a little too hard when it reached the end… and Newton’s Laws can be a bitch sometimes,” she said unapologetically.

“Not that I don’t love how this conversation is going, but can we get back to the search efforts?” asked Agrippa.

“Sure. I finished building the backup data centers for your military drones. Each one has a real-time backup link to the Outpost, so if they get damaged or destroyed, they can be restored immediately to a new drone,” I said.

“Excellent! I’m going to start full-blown combat training drills for the Wasps and Scorpions. We have enough to handle training accidents.”

“Backups for the NI-5’s,” said Zia. “That’s brilliant. I’m assuming they gain tactical experience from training and actual combat?”

“They do,” said Agrippa, his voice quite smug. Having mechanical drones fight for you was one thing; having actual thinking, learning pilots that couldn’t die was another. Every single engagement they would ever fight would only serve to make them better the next time they fought.

“Well as much fun as this is, I’ll send over the ideal search pattern once I’ve finished it. I want to get back to the gravity pods. I feel like I’m close to a breakthrough.”

With that, the impromptu conference broke up.

“You’re no fun,” griped my best friend. We had been best friends since grade school, when they moved to our town and his parents had joined the church. It was a common complaint; he would find some ridiculous adventure to drag us on, I would protest until he wore me down through sheer persistence. But this time, I held my ground.

“I am NOT jumping off the cliff. I don’t care how many times you’ve done it already.”

It wasn’t literally a cliff, it was just called a cliff by the locals. It was more of a low overhang, a chunk of boulder and dirt that leaned out over a deep creek. It was no more than twenty feet up at most, depending on the water level of the creek, not much higher than the high dive at the county pool. I’d heard a kid last year broke his leg when the water level was low, but I didn’t put much credence to it.

“You’ve got to try it at least once! It’s easy, and you won’t get hurt,” he pleaded.

“You said that about roller derby, and I twisted my ankle and fell on my ass in the first five minutes,” I pointed out.

He rolled his eyes. “Okay, one time I was wrong.”

“And the rope swing you made last summer? I nearly faceplanted on the shore while you were making eyes with that guy instead of pushing me.”

“Hush!” he said, looking around furtively to see if anyone overheard. It was a reflex for him; we were alone on the shore, and it wasn’t much of a secret according to the high school rumor mill, anyway. “Okay, so twice.”

“Oh yeah? What about when you got me to climb a tree when we were little? Weren’t you supposed to catch me?” That little escapade had resulted in a broken wrist. With that reminder, I was even more convinced this time to not follow his lead. I’d spent too much time planning my escape from my mother and her psycho ‘faith’.

“I was little, I didn’t know any better,” he deflected. “And besides, you’re a lot heavier than you look.”

I huffed. “You’re a lot scrawnier than you admit.”

“Bitch.”

“Slut.”

“Tramp.”

“Man ho.”

He wiggled his eyebrows. “And then some,” he said with a grin. “Fine, if you’re not going, wait here.”

It only took a few moments before I saw him at the top of the cliff. He jumped off, but just before he hit the water, I heard an “oh, shit!” I jumped up from the towel I was sitting on, in time to see him surface and flailing his way towards shore. With every flop of his arms, I heard a litany of curses. I rushed out towards him, only getting waist deep by the time I reached him.

“I think I broke my leg,” he said, leaning on me heavily.

“The water does seem a little low,” I observed unnecessarily.

“No shit, you think?” he sassed. “Fuck, this hurts. My parents are gonna kill me.”

“Come on, cliff-diver. Let’s get you dried off and dressed. I’ll drive you to the hospital.”

I left off the “I told you so”, but I knew he heard it anyway. Just one more piece of ammunition for the next crazy adventure he found for us.

The probe looked like it was in really bad shape. It had originally been a forty-meter long cylinder, with an eighty-meter wide solar sail that also acted as a shade for the delicate electronics. A large mass of tubes extended out the opposite side, a complex but robust radiator system to cool the craft. The sail had been intended to be retracted once far enough from the sun, as its cooling gains and minor speed boost not worth the likelihood of micrometeorites damaging it.

But the sail was out and shredded, dragging behind the probe. The radiator tubes were bent, and several holes could be spotted in the probe. I couldn’t figure out how it was even broadcasting at all.

“Not much to look at, is it,” said Agrippa. It had taken him four months to locate it. Sakura had found a simple cubesat telescope design that was cheap and fast to produce, and had pumped out a few hundred thousand of them. Agrippa had spread them with his assault drones as they moved around for training, and when arrayed together, had given us a great tool to search the solar system. NASA would have been jealous of the high-fidelity, high-resolution images we could capture and analyze of the solar system now. Even still, it had taken us two months just to get the telescope working, and we’d needed to bring another NI-12 online just to operate it.

“It is definitely damaged,” said Optio, his deep voice rivalling Agrippa’s for gravitas. “It is on course to slingshot around Jupiter in six months, and will return to Earth orbit in three years. Unfortunately, I cannot calculate a good trajectory for intercept, unless we purpose-build a rocket.”

“And what if we were to aim for Earth directly, and intercept it there?” I asked. Three years wasn’t exactly a long time when you had all the time in the world.

“That would probably be easier,” acknowledged Optio. “Now that it has been located, I would like to continue expanding the telescopic array and searching the solar system. I have been lead to believe that we think the aliens might have a mother ship.”

“Go ahead,” I said. This probe was starting to feel like a red herring. Or was it a trap? Was it meant to draw us out? In some respect, it had done exactly that. But if we didn’t meet up with it as it entered the solar system, but were instead at Earth before it arrived, it would be much easier to hide where we were at. Space was big, and we were very, very small. The aliens had really weak sensors. I could see how watching the probe could make it easier for them to find us. I still couldn’t believe that they didn’t know where their own ship had gone, and 1035 Ganymed wasn’t small or hard to find. Maybe the aliens were prospectors, just landing on random asteroids to look for specific materials? I shut down that line of speculation. I’d been down that road many times, and the lack of answers was only building my own paranoia.

I turned my attention back to my own lab, and Zia occupying her own corner of it. Zia looked over at me, and said, “do you have a few minutes?”

“Sure.”

“I figured out the gravitic plates,” she said, a broad smile on her face.

“That’s great news,” I said.

“Well, I finally figured out the spectrograph readings we took.” Zia sent me a report linked to the odd spectrographic tests we’d done.

“It appears to be carbon,” I said, not understanding.

That made no sense. The plates in the primary pod slung under the fusion reactor were each three meters long, but accounted for a full twenty percent of the weight of the entire alien craft. The remaining pods had much smaller plates, but accounted for another ten percent. Much of the framing of the central trunk of the craft had been built to hold up their massive weight. Carbon simply didn’t weigh that much.

“How is that possible?” I asked.

“Well, it’s mostly carbon,” she amended. “There seems to be a layer of iridium.”

“So it’s the iridium that makes it heavy? The density is much higher than carbon.”

“Oh, that’s the heart of it,” said Zia. “The density is completely off the charts. The atoms are extremely compressed, yet still maintain their physical properties. It’s like they squeezed 100 carbon atoms into the space one should take up. The iridium is less compressed, although how much, exactly, I can’t be sure until we can cut one open and get it under the electron microscope. But that makes sense, really, since iridium is naturally extremely dense to begin with.”

“So how could a species that has such crude materials science able to create such an advanced metal?”

Zia shook her head. “I think the better question is, what happened to the race that created these plates, and how did the aliens get ahold of them?”

The implications of her statement struck me. We had only encountered a single species. But the enemy were intergalactic. It hadn’t occurred to me that this wasn’t their first encounter with a new alien race, like it was for us. In fact, their rapid deployment of kinetic bombardment indicated that not only were they violent, but that they’d had violent experiences that made this approach seem reasonable. From their perspective, they could be the heroes who prevented a long, drawn-out war over resources with a ‘primitive’ alien tribe. They almost certainly wouldn’t see themselves as the genocidal monsters they are. And if we weren’t the only species out there that had dealt with them, then we might have, at some point in the future, some allies we could enlist.

“Okay, but I know you,” I said, seeing the smirk on her face. “You’ve figured out more than you’re letting on.”

“Well, I haven’t worked out the math yet. What I have puzzled out is staggering, and you should plan on giving me a Nobel Prize soon.”

“There wasn’t a Nobel Prize in mathematics. There was a Fields Medal.”

“I know, but this stuff makes me the reincarnation of George Boole.”

“Great,” I said. “So what is it?”

“I applied current to both plates.”

“Which created a gravity field, yes, we’ve figured that part out.” Explosively, in fact, when the pod had destroyed transports and dented 10-meter-thick steel floors.

“Right, but I figured out the correct current and voltage to manipulate the field, and placed a block of carbon between them.” Zia lifted a thin plate of carbon, diamond-hard, from the table. It was roundish, and looked exactly like you’d expect a cube to look if it had been flattened.

“So you need gravitic plates to create new plates?” I asked. Zia nodded. “So how were the first gravitic plates created?”

“Ah, so now you understand the mystery!” she gave a wide grin, clearly delighted at the puzzle. “And that is why I’m working on the mathematics, so that we can fully understand the mechanics.”

“So what practical applications can we use this for?”

“Well, we could use it as a localized weapon that causes crushing gravity between two points, or heck, even as a molecular knife to slice off atom-thick layers. Maybe as a field that can lift or move objects. Once we have the math figured out, the sky is the limit. The best I can tell so far is that the aliens had a precisely calibrated gravitic field that was aimed at two points above the ship. So the ship was constantly ‘falling’ in the direction they wished to go. Want to speed up? Increase the power of the field. Want to stay in place, hovering over the Pacific Ocean? Balance the gravity field to oppose Earth’s gravity exactly.”

“Hmm, so we could counter-balance, say, a drone with a small plate that would allow it to hover, and angling the plate could allow it to move in the direction you wanted it to go?”

“We could,” she allowed. “We theoretically use something like this to move just about anything. Even something… oh damn, that’s how they did it. Those bastards.”

“Did what?” But then I realized, and held my hand up to forestall an answer from her as realization swept through me. This was how they moved the asteroids. All it took was a large enough array of gravitic plates, and a sufficiently powerful fusion drive. And now we knew how to do it, too.