"Jackson. How bad is it?"
"The converted stations are firing on our ABM systems. We can take out the converted installations eventually, but more rockets are going to get through now that our missile defense has been reduced."
"What about here?"
He gestured to the screen. Our forces were fighting the full drone airforce, and it wasn't going well. The converted mass driver fired again and again. By the time the ground forces arrived we would be personally under siege.
He decided to pile it on. "It looks bad. It gets worse. Multiple launches. This time ICBMs all directed at us."
I looked at the ceiling again, this time judging how many nuclear strikes this old bunker could weather. I guessed about one. "How long?"
"Thirty-five minutes. The constructs will be here before then." Helpfully, he highlighted the ICBM locations on the projection. The plain red dots looked like they were underground now, but they rose slowly. Burrowing to the surface.
I looked at the machine. Was there something we could send that would make a difference now? Screw mental and temporal safety, I had to try. I completed my earlier draft message, and sent it.
It appealed to whoever read it to do something to prevent this catastrophe. As a test I requested that the unknown reader contact me at an old anonymous email address on this date. Amazingly, the island still had a weak connection via satellite. I checked the account. Nothing.
I read over Mechaner's message. It was short, and not that exciting. The first part explained the situation succinctly, and exhorted him in an unusual fashion. The second part was larger. It contained a number of short, cryptic hints. Each was more a verbal Rorschach blot than a message.
There were some sections of actual code, though even that was compressed to near illegibility. I stood and paced. The magical girls watched me anxiously, Eva's hand on her carbon fiber sword. I shrugged, vaguely disappointed at not feeling brainwashed. "I don't have anything. Didn't seem to change my goals or give me any 'great' ideas."
I walked over and sat next to them, trying to look non-threatening. Amaterasu sat next to me. I pulled her in close and kissed her. I wasn't feeling particularly romantic, but I thought it might cheer her up. That was worth something. Plus, it seemed like a good way to go out.
Eva raised her voice, calmly interrupting us. "We need to seriously revisit our options. Specifically, ending the world."
Amaterasu sounded incredulous. "Why would we? Even if we've lost, why would it help to guarantee our death?"
"Ending the world will cut off the world-lines that branch from this point. Since pretty much all of those will be completely dominated by Pando, we increase the share of worlds where Pando isn't dominant."
Lina wore a feral grin. "I agree. Take them with us."
Dr. Edelstein started to say something, then stopped and raised his hand. I gave him an odd look, but waved him on. "What about aliens?"
Lina stared. "Um, what?"
He continued eagerly. "What if there are aliens? We might be doomed, but is it right to take away the aliens' chance?"
I answered. "If the aliens are out there, what are the chances they'll withstand an outcome-pump empowered Pando? If they had an outcome pump wouldn't something similar have happened to them? Do we have as much responsibility for their alternate world selves as for the ones on this branch?"
Eva paced once, then stood still. "We can't assume aliens exist. I agree that evidence suggests that either they are technologically inferior, and likely to be so when Pando expands to them, or they don't exist.
Moreover, the constructs are attacking us out of proportion to our military importance. Multiple ICBM launches just for us? Maybe they fear we will end the world. This may be our last chance to make a difference."
The mountain shook nearly constantly now. Thin tendrils of dust sparkled in the projector's light.
I turned to Jackson, who had been unusually quiet during this exchange. "Do you think there any hope of escape or victory?"
He pondered for a minute. "Your father is leaving in a small submarine. I expect there will be a short period where you could find unmolested lesser bases in the ocean. He has offered you a place on the vessel. However, the constructs have already activated at least two observer devices surrounding the island. I suspect that the island is ringed in them by now. As for victory? No. We lost that hope when they managed to spread to space."
I asked, genuinely curious, "What about you? I'm sure he offered you a spot."
Jackson smiled. "I turned him down."
I gave a gruff nod. He had chosen death at my side. What did you say to that?
Amaterasu asked, "What message would we send?"
Eva answered. "We could send the original message. Maybe we have to send the original message. It depends on what type of consistency is required."
Amaterasu shook her head heavily. "Okay, but not until we have to. Try to think of something else."
I agreed. "Not until the last minute. We need to set up though. We don't want to get interrupted."
We wrote two messages and sat in a circle, holding hands. We would try the changed messages first. If that didn't work, we would try the original messages. It was a gamble. As long as we started the ritual we couldn't be interrupted, but we were vulnerable between rituals.
Amaterasu couldn't send the second message, as she had promised not to. It made more sense - why I was here. Why I was needed.
While we prepared, the last of humanity's orbital weapon installations were converted. Jackson spoke. "They are in the fortress." Distant explosions lent weight to the simple pronouncement.
I shuffled my feet. I wanted to pace, to try to think of a way out. I looked back to the ceiling. The red dots indicating incoming ICBMs had risen to their peak and were falling now.
The giant mass drivers spoke silently once more. The mountain shook again; the camera survived, but with a slight tilt to its view.
The falling stars reminded me of Mechaner talking to his psychiatrist. The meteor that Pando had predicted. Now different falling stars proved Pando right again.
Why a meteor, though? Surely there were easier, more convincing tests. A lottery. Stock prices. What did those have in common?
They were chaotically determined. A slight change to the past could butterfly-effect them out of control. A meteor? No butterfly would change a meteor's course through the vacuum.
Maybe the meteor was a sign of weakness after all. If the world wasn't perfectly determined, then what was it? A perfectly determined world would be where world A sent back the exact message that lead to world A.
A loop? World A sends a message that causes world B that causes world A? But all possible worlds existed, unless pruned by the machine. Not one ground state, but many possible states, each possible as long as they tended to turn into each other. A closed set of possible worlds. Worlds A,B, and C: each could send a message that would spawn one of the others.
Eva spoke. "It's time. In case the ritual fails we need to leave time for the second attempt. They've almost reached this chamber."
I nodded slowly, but my thoughts were still elsewhere. Eva looked around at all the girls, and each nodded. Lina smiled, oddly triumphant. Amaterasu tried to smile too, but didn't quite succeed.
I stopped them. "Wait. I might have an idea." I continued, thinking aloud. "The meteor wasn't chaotic. That indicates Pando couldn't perfectly predict the future. That means we aren't destined to do this. It also means Pando could have a weakness."
"What weakness?" Eva asked.
"I don't know. I'm just thinking aloud. If there was one message and one outcome, then Pando could have predicted something more blatant than a meteor. What if there are many possible messages, each that could lead to the other messages being sent. A closed set of possible worlds. Once you entered that closed set you wouldn't get out, so it would be a likely end state."
Edelstein jumped in. "As I mentioned in my report, when you send a message the Machine prunes world-lines that don't contain that message. But Mechaner described the action of the message ritual as adding to the probability of the world-lines that contain that message. Could the first machine work similarly? Just more crudely?"
Eva shrugged. "Still, it makes sense that the message that dominates the most world-lines will be the one that maximizes its own probability. That set of possible messages will be those that prevent outside messages from being sent."
I nodded, still watching the descending red dots. "So if we want to find ourselves in a universe where what we desire occurs, we need to monopolize the message sending. Can we find another candidate message or sender of messages to monopolize the world-lines? One more benign than Pando."
Amaterasu asked, "What makes Pando special?"
"Exactly!" Edelstein nearly spit. "What properties does Pando have that allows it to spread and take over?"
Eva tapped her fingers. "The constructs were directly created because of the message Mechaner received. They became more intelligent because the Machine pruned outcomes where they didn't act intelligently. So it was more likely that they actually become intelligent than that they randomly act intelligent."
"Once they are intelligent, they spread throughout our universe and ensure that no one else can send a message," I added.
Lina asked, "But how did they actually become intelligent? It didn't just happen."
"No. It didn't just happen. They absorbed computers. Using that existing processing power was a more likely path than spontaneously developing their own computing hardware."
Something very heavy hit one set of doors.
I mused. "Could we create an AI? Drive it forward with a spell to impel its success?"
Edelstein shook his head. "We can't create our own spells. Mechaner programmed them all in when the Second Machine was first instantiated."
Amaterasu asked, "Are there any rituals we could use?"
I shook my head. "No. Nothing like that."
Lina nodded. "So is there anything else that already exists?"
I was about to say no, but Eva interrupted. "The censor."
I looked at her and blinked twice. "The censor. Good point. It has a difficult task that requires it to act intelligently. It has a spell that impels it to succeed. Remember how much more successful it became at its task?"
"Can we turn it against Pando?" Jackson asked. Most of his focus was still on directing the defenses.
Eva answered. "Its goal is destroying images and footage of magical girls. If a magical girl alone is going to see it, then it doesn't destroy it."
I added, "And it identifies what to spare independently of time. It prunes world-lines where the virus fails to destroy pictures of magical girls before non-magical-girls can see them.
So Mechaner shows up on camera when just I am looking at the screen, but censors it when someone else looks. Or when I look away. That means there are more world-lines where it succeeds if it preemptively destroys footage that magical girls are never going to see."
A huge explosion shredded the double doors. The corridor beyond was almost unrecognisably scarred. Amaterasu blocked the shrapnel, then Solid Light Reformationed the doors. I could see the constructs trickling back into the corridor through the translucent barrier.
"How can we actually make it hurt Pando? Make Pando start taking pictures of us?"
I shook my head and grabbed my laptop. "No. Make Pando into a picture of us."
"Eh, what?" Lina looked at me with concern.
"What is information? A onetime pad encrypts a message by XOR-ing it - that is, combining it bit by bit - with a random message of equal length. Now you have two pieces of information that are both necessary to extract the original message.
I know the censor will delete the onetime-pad-encrypted pictures of magical girls, but not the random key. For any piece of information I could make a key that would output a picture of the magical girls. So why hasn't every piece of information in the world been deleted by the censor? It must have to do with what direction the information flows."
Scraping sounds came from the other entrances to the room. Jackson spoke. "I'm collapsing the corridors." Through the ethereal double doors I saw a bright flash, followed by rubble filling the hallway. The no longer steel doors bowed outward from the weight. The cavern shook worse than ever before.
I continued. "You have the picture, originally. The encrypted picture is derived from the picture, so it is deleted. The random key is not derived from that information, so it isn't deleted.
How could it know that the encrypted picture is derived from the original picture? The simplest way is time. The encrypted version comes after the original picture."
I typed rapidly, nodding towards the constructs clearing the rubble from in front of the double doors. "Hold them off." I continued explaining rapidly. "There was a significant section of gibberish that preceded the message Mechaner recognized. Mechaner's message included sections of code used for all his minions.
He didn't give us the gibberish, but what if it wasn't random? I can send a key that would decode the sections of minion code into a magical girl picture, then send the magical girl photo.
The 'key' will predate the magical girl photo, and the 'encrypted picture' will postdate it. I don't know for sure how the censor recognizes what to delete, but if it takes time into account it would think the sections of code are actually encrypted pictures of magical girls."
Eva pulled her blades free, running her hands over the shining composite. "Wouldn't it have already deleted the constructs' code if that was the case? We would have already known."
"Ah, but it doesn't delete pictures of magical girls that magical girls are going to see. At least as long as other people aren't also seeing the pictures. After the magical girls view the pictures, it won't preserve them.
We have the only copy of the message. If we decode the picture, then we would view it before any non-magical-girls. If we then show it to Jackson, it should be deleted.
"We don't have the 'gibberish' from before Mechaner's message. Couldn't we have sent something else entirely from the last universe?"
I shrugged. "If so, then we are giving a new universe a chance. It depends on how similar the universes in the closed set, or whatever multiverse topology, tend to be. We are about to find out. Or maybe not, depending on how the anthropic principle applies here."
Eva paced in front of the door. Amaterasu renewed the Solid Light Reformation, then resumed firing Rainbow Resonances through the translucent structure.
"How long?" she asked, gasping with the effort.
"Just a few minutes." I had barely completed my words when the constructs detonated the shaped charges at all the other doors. Amaterasu shielded against the blast for an instant, then dropped the shield to allow Lina's Scintillating Fusillade to fan out.
The constructs streamed in despite the attack. "Ama, get ready to shield the whole machine!" She nodded once and moved to the center of the machine. I looked around to make sure we were all within the radius. "Go."
She raised her hand. "Perfect Full Rainbow Reflection." The constructs slithered forward. They were nearly pure wire - the weaponry had been stripped from them by the fire and falling rocks.
I typed furiously, editing the team picture Amaterasu had insisted on. We all had disguise fields active in that photo, so it might have a higher priority. It was nearly undecipherable when shrunk to this low a resolution, but I didn't think that would matter.
I couldn't help glancing up from my work. Amaterasu stood her ground, sweat beading on her forehead. The constructs linked together into a giant wire snake, encircling the shield. The Rainbow Reflection slowly shrunk under the constriction.
The red dots above fell faster and faster.
I pulled out the memory card and jammed it into the Machine's console. One dot arrived. It felt like the entire mountain dropped three feet. A huge chunk of rock fell from the ceiling and bounced off Amaterasu's shield.
She dropped to one knee with a groan. The shield receded a foot. Any more and the Machine would be peeking out.
I navigated the console urgently. The parallel to Mechaner's last moments was not reassuring. I hit enter. An alarm sounded and a warning light appeared. The shock had broken something.
I pressed my hand to the Machine, calling desperately, "Retrograde Entropy Sanction!" The Machine hummed briefly, a slight chime indicating success. I quickly took the copy of code and decoded it with the key I had sent.
A fuzzy picture appeared. I looked at it, then turned it to Jackson. The picture scrambled. It worked.
Now the question was, had the world that spawned ours sent the same key? How similar were the worlds in the set, if that model of the multiverse was even correct? Would the censor be any better than Pando even if all went as planned?
The constricting multicolored bubble forced us all together. I held Amaterasu's unoccupied arm, helping her stand up. We huddled under the shrinking sphere, surrounded by countless foes. Each of us gave a last nod or smile and looked to the ceiling.
The camera at the top of the mountain had been destroyed, but the missile tracking overlay still functioned. We could no longer see the true stars, but the false ones still fell. Little fusion warheads, waiting to be a star for one glorious instant.
They descended a little more. What type of universe were we in?
The falling stars blinked out.
The constructs around us collapsed into twisted piles. Amaterasu dropped the shield. We trod mutely over the inanimate whorls of steel. I broke the silence by addressing Lina. "I've been thinking. With my gravity power, if I balance the pull from the sun, moon, and sections of the earth correctly..."
I paused as we reached the blasted entrance to the tunnel and looked out over the cratered island. The moon dimmed slowly as the sun rose above a watery horizon.
She raised an eyebrow. "Yes?"
"I should be able to fly. Or at least jump really far. Have any tips?"
She smirked a little. "Aren't you afraid of heights? You tend to close your eyes when I fly you around."
"Well, I've always wanted to get over that. No time like the present!"
Lina shrugged. "Sure. I'll catch you if you screw up too badly."
Eva laughed lightly. "You might still want to cast Retrograde Entropy on yourself first."
I waved to Jackson. "Where are the nearest injured?"
He pointed and highlighted the location on my HUD. I decided to assume that he barely managed to choke back an inspirational speech.
I turned to Amaterasu. "Good luck kiss?"
She rolled her eyes, but obliged. I followed Eva's suggestion, then took a deep breath and stilled my shaking hand.
I raised my fist to the moon. "Cardinal Impulse Augmentation!" I flew. It was only for twenty seconds, but that's better than the Wright brothers.
Thanks for reading! I hope you enjoyed it. If you have any questions or comments, let me know. I may post a followup addressing the mechanics of the universe and answering any questions raised.