“We will save the multiverse,” Twilight Sparkle said. “Timelines are falling at a considerable rate, and if allowed to continue, the entire multiverse will eventually crumble.”
She stood next to a chalkboard that bore, in big letters, the words Save the multiverse. The other four sat on cushions in a semi-circle around it. Each levitated a small folder containing a few pages of notes.
Crystal Faire flipped through a few pages and then set her folder down. “Right. We must come up with a plan if we are to tackle this.”
“I’ve identified three main goals: one,” Twilight said as she turned and started writing on the board, “we’ll need to prevent any more timelines from colliding with each other; two, we have to find a way to control all this multiversal debris floating about; and three, determine the cause or causes behind all this and correct them as soon as possible.”
Starlight Glimmer frowned and shook her head. “That sounds like an awful lot. How are we supposed to do any of that?”
Twilight smiled. “That’s what we’re here to figure out.”
Sunset Shimmer hummed. “Crystal, could you go over what you learned about those holes in the timelines? I think that would be a good place to start.”
Crystal nodded. “Twilight’s put quite a bit of it on page seven,” she replied as she picked her folder back up and opened it. Pages rustled as the others turned through their respective binders. “They’re four-dimensional holes, as far as I can tell. They’re as wide as the amount of space missing and as deep as the amount of time that space is missing for.”
“Yeah, right. The bottom of the hole is the part furthest back in time, right?” Sunset asked.
“Yes. Through most of the collapse, the timeline just disintegrates... The debris only appeared when the holes in the timeline reached some crystallized portion. It couldn’t collapse anything beyond that.”
“So, it’s from that interaction with crystallized portions of the timeline,” Twilight said.
“Maybe we could use that,” Sunset said. She lit her horn, and a Y-shaped image appeared in the air in front of her. “If we had two timelines that diverged from each other and they’re each collapsing—” the top spokes started to disintegrate, “—we could just pick the point of divergence and crystalize that—” the bottom half of the Y turned crystal, “—and… we’d get only one set of debris from two timelines.”
Twilight watched as the upper spokes on Sunset’s Y crumbled and met with the bottom crystallized portions, and then, as pieces of debris floated from the boundary at the center, she nodded. “That could be useful. That would minimize the amount of new debris that we would have to deal with.”
“We could deal with entire sets of timelines that way,” Starlight suggested.
Crystal crossed her forelegs. “But we’d have to be careful. Every moment further back we put the stop is another infinitely many probabilities that’ll collapse with it.”
The others hummed in response.
Sunset returned to her seat. “Well, at least we have something. We could figure out the details later, right?”
“That’s right.”
“So, what about the debris that’s already out there?” Starlight asked.
“Yeah. As long as that stuff is still there,” Sunset said, “it’ll rip apart more and more timelines.”
“So then, dealing with that debris is our top priority,” Twilight said.
Crystal hummed.
* * *
“No matter which way I look at it,” Crystal said, “I can’t hope to do anything about the debris unless I can get a clearer picture of what’s going on inside those holes first. That means finding more holes so that I can do tests on them.”
Twilight’s muzzle twitched. “Right. But… I guess that actually finding them is going to be difficult.”
The five of them trotted through the shadows of the high-rising trees above. The dirt pathways that served as streets flowed and snaked, occasionally branching off into two. Some paths ended at stone buildings that sported intricate sculptures built into their sides.
Crystal led them down the path. The ponies in the streets, all dressed in garb with frays and washed-out colors, paused within their comings and goings to watch them as they walked.
Starlight frowned. “I didn’t know anypony even lived in Hollow Shades,” she said.
Chrysalis kept looking around. “I thought they would have scurried away by now just from the sight of me.”
“These ones are special,” Crystal said, “and not for the reasons that you would think.”
“Hmmm, nonetheless,” Chrysalis replied. A green flame enveloped her. Gone were the holes in the legs and the dark-green mane. In Chrysalis’ place, a blue unicorn mare with a whitish-paletteted mane and tail stood in her place.
Twilight raised an eyebrow. “That disguise looks an awful lot like me, aside from the colors and the… freckles,” she motioned to her face.
“Hmmm, yes. I spotted this one in one of the timelines that she showed us. You will refer to me as Silverlay while I am in this form,” Chrysalis, or rather Silverlay, said.
Twilight pursed her lips and nodded. “Silverlay, huh? That name is familiar. I wonder…”
Sunset and Starlight glanced between each other and giggled.
Sunset shook her head and caught up to Crystal. “So hey, uh, didn’t you say that you can filter out what you can and can’t see?”
“I did,” Crystal replied as she looked about the town.
“Can you filter based on timeline state?” Twilight asked.
Crystal hummed. “I already do for timelines with crystallized bits. Of course I can.”
Sunset nodded. “Okay, for sure. Could you maybe do something like that to see which timelines are collapsing?”
“I suppose… I haven’t exactly worked out how I’d do that yet.”
“I guess you could always derive it from the filter you just mentioned,” Sunset said.
Crystal’s jaw twitched from side to side. “And I do have an alternative in mind if I can’t, but I think I can do it.”
The four watched as Crystal peered over some bushes to their side and then they peered over them for themselves. They spotted an unassuming building across the street. A pair of glass windows and a wooden door were the only things not stone about its front. Two ponies, Blueblood and Pinkie Pie, sat hunched underneath the windowsill.
Crystal watched as the two pressed their ears against the bottom of the window. They slinked away from the window and scrambled into a nearby alley which contained little except a box at its end. After that, they went silent again.
“It’s just…” Starlight whispered, “no matter what we do; if we have to go to some timeline to watch it collapse, it’ll… collapse.”
Twilight shuddered and folded her hooves together. “Yes… oh, I wish there were alternatives…” she lamented.
Pinkie Pie and Blueblood whispered between each other for a moment before the former shoved the latter into the box and then climbed inside herself.
“All I need is enough time with one to see how the holes work; more than the scant few hours with no preparation that I had with them before,” Crystal whispered back. She narrowed her eyes and said, “I’ll be better prepared this time.”
A few moments later, a trio of diamond dogs, two wearing rough-looking armor and the third adorned with gold all around, burst through the front door. They started sauntering up the street with what looked like an orb in their possession. Soon after, a pony wearing a cloak that covered them from head to hoof also emerged and started down the street in the opposite direction.
Crystal lit her horn, reaching out with her magic to grab objects that each of them carried: an orb from the trio of diamond dogs and a pyramid-shaped object from the pony in the cloak. Said objects then teleported into Crystal’s waiting hooves where she observed the both of them.
She wrapped both of the objects within her magic and then, with a large amount of energy, crushed them. The orb shattered with no fanfare but the pyramid screamed and a wistful smoke rose out of it and eventually dissipated.
That takes care of Sh"rk’Moil, Crystal thought with a nod. She then turned to the others and said, “More to that, we will need to know what timelines are collapsing anyway if we want to catch all of them.”
Sunset frowned and leaned on the bushes. “Then I guess it’s just as well.”
* * *
Sunset glanced down at the tea set, mentally shook her head, and then floated it over to Chrysalis in the adjacent cushion. “So, like, I have a question.”
Crystal took a sip from her tea and nodded. “I can see a timeline moving with my mind’s eye, but I can’t filter for it.”
Sunset scratched her head. “Okay, I guess. But we need some way of knowing how the collisions work.”
Twilight sat up on her cushion. “Wait. What about what we all saw in Chrysalis’ timeline? Crystal, can you filter for that?”
Crystal’s muzzle twitched as she thought. “Hmmm. I suppose if I used that Rapid Status Change Filter that you came up with. Why do you ask?”
“So we would know which timelines have already collided with each other. We’d probably want to know that, right?”
Sunset gasped. “That’s super helpful, actually. We could find patterns in what’s collided with what to predict what collisions could happen next.”
Starlight cooed with interest and said, “Hey, I see what you’re saying. We could even reconstruct what’s happened so far. Maybe we’d even find whatever started all of this in the first place?”
Crystal nodded. “That sounds interesting. But I could see the actual implementation getting… very specific.”
“Maybe Twilight and I could help you out with that,” Sunset said.
“Maybe.”
* * *
Starlight wiped some water from her eyes but that made them no less heavy. She had to make it back to her bed. She had to see the progress more.
She trudged along, and as she rounded a corner, she finally saw some light within the castle’s darkened halls. Said light streamed through an open doorway and fell on the carpet. She approached the open doorway and peeked inside.
Crystal, Twilight, and Sunset stood gathered around the chalkboard. Several candles around the room lit the space just enough for them to see. They spoke in hushed tones and passed some pieces of paper between each other and then pointed at the chalkboard.
A quick glance revealed several strings of symbols across the chalkboard. Some of them looked like magical runes, and she understood those by themselves, but the others held no meaning to her whatsoever. She even spotted a few numbers and some symbols that she knew were mathematical in nature, but she could not guess what significance they bore.
A nearby table held several stacks of papers. Twilight giggled and then levitated the sheets that they had been looking at onto the stacks before adding some symbols to the chalkboard. She then floated over some new blank sheets of paper from another table across the room, distributed them to Crystal and Sunset, and then resumed saying something that involved the word parameters. Sunset responded but in a tone so hushed that Starlight could not make out anything.
And that was okay. Starlight stepped away from the opening and trotted back down the way she had come.
* * *
Twilight glanced up at the dark clouds that hung over Canterlot. She then turned her eyes toward the hulking yeti-like creatures in front of them. Their foes wore armor that covered their heads and their midsections and they all carried spears and shields.
And Crystal suddenly appeared behind one of them (whether it was teleportation or just unfathomable speed was not something Twilight could distinguish) and kicked them into a nearby building. She disposed of the other one just as quickly.
After examining her work, Crystal turned to them. “I don’t have anything yet on how to deal with the collision issue. It’s not like there exists magic that can control an actual timeline.”
Sunset scratched her head. “Well... working with crystallization and threading is all we have…” she mumbled.
Crystal nodded and turned down the street. The others followed closely behind.
Canterlot itself was rife with broken windows and many buildings had holes in their walls and roofs. A few black banners hung from the occasional wall, each displaying a pointed crest that looked like a pair of lightning bolts. Aside from the creatures that they now walked past, the streets were empty.
Silverlay, in particular, considered the fallen creatures. “Hmph. You would think that after besting my invasion, those oafish ponies would have taken their defense a little more seriously. I guess I was wrong.”
Twilight blushed and scratched the back of her mane. “You know… I really am starting to think that we’ve been pretty lax about defending ourselves. What with all the threats that I’ve seen and had to deal with.”
“And Fizzlepop is quite the formidable opponent. She’s a gem once she’s on your side, but alas…” Crystal said with a chuckle.
Twilight raised an eyebrow. “Formidable? That’s a compliment coming from you.”
“You’re telling me that she defeated three princesses in sixty seconds and conquered Equestria in a day,” Sunset said as she glanced around the ruined city.
“But I do contend that those are rookie numbers,” Crystal replied. “I’ve seen it done in less. I’ve done it in less—for instructional purposes, of course.”
Sunset frowned. “Still a lot faster than what I was going to manage with my plan,” she grumbled.
“Equestrians really are weak,” Silverlay snorted.
Starlight deviously grinned and leaned in close to Silverlay. “Equestrians beat you twice in a row.”
Sunset snickered in response.
Silverlay’s expression rapidly deformed into a snarl and she pressed herself muzzle to muzzle against Starlight. “Do not make me hurt you,” she growled.
“Chrysalis,” Crystal interrupted.
Silverlay whirled around to face Crystal. Her eyes were still like slits.
Crystal peered around the corner of a nearby building as she tracked some bodies making their way across a nearby street. Said bodies turned out to be a bipedal cat, bird-like creatures, and a hippogryph. Spike and the rest of Twilight’s friends hung closely together with them.
Once they disappeared, Crystal nodded and stepped into the street herself. “There is one thing that I know: even after visiting your timeline, threading it, even... that didn’t stop it from colliding again.”
After a moment of staring Crystal down, Silverlay nodded and followed suit. “Then your threading technique isn’t going to help.”
“No,” Crystal affirmed.
The five of them continued through a few alleyways, heading in the direction of Canterlot Castle where the clouds were the thickest. The occasional storm guard blocked their path. Said storm guards were promptly sent flying down the street, courtesy of Crystal.
While Twilight, Starlight, and Silverlay watched the short exchanges and overall took in the disarray the city was in, Sunset kept her gaze toward the ground. She muttered a few words to herself here and there but overall kept quiet.
The space above the castle brightened up as a bolt of electricity shot into the sky. It disappeared into the clouds and the clouds, in turn, began swirling about at velocities that would have made even Rainbow Dash cringe. The air howled in their wake and the five of them could feel fleeting hints of its power even from their distant position.
“Ah,” Crystal said, “here we go.”
Crystal threw up a barrier around them and the five continued closer to the castle. The increasingly harsh winds outside the barrier picked up pieces of debris and slammed them together, wherein they exploded into even smaller pieces. Several pieces of debris bounced off Crystal’s barrier, but it yielded to nothing.
“The protective barrier does work, huh?” Sunset mused.
Starlight rolled her eyes. “You would think that’s what it’s for.”
Sunset shook her head. “I just think it would be nice to have something like that for a timeline. Something that protects it from damage.”
Twilight nodded and glanced up at Crystal. “Do you have anything like that?”
Crystal groaned. “Not a chance.”
Silverlay shook her head. “Pity.”
Crystal stopped in the middle of the street just as a wooden cart bounced off her barrier. She glanced toward the gales above and then, when a gigantic boom sounded from down the street, watched as Spike and Twilight’s friends arced through the air and into the castle throne room. She nodded. “This will do for a moment.”
Sunset continued stroking her chin. “Well, if you can’t do that…” She paused for a moment more and then gasped and slapped the ground. “Wait, I think I’ve thought of something.”
Twilight leaned over. “Yes?”
“Say you had a crystallized timeline and some other timeline collided with it. What would happen?”
Silverlay tapped her chin. “Hmmm, right. Yes. If that timeline is crystallized, then it is set in stone and can’t be changed.”
Twilight gasped. “Oh! I see where this is going! It’s—”
“There won’t be anything going between these two timelines like what happened with mine,” Silverlay finished.
“Because nothing enters or leaves this crystallized timeline, and same thing with the uncrystallized one as a result.” Starlight said. She then scratched her head. “But that helps us how?”
“Those crystallized parts are rigid and unmoving and are probably impervious to damage,” Crystal said.
“But did my timeline not have another collision?” Silverlay asked.
There was another loud roar as sections of the castle’s ceiling caved in. Crystal regarded it carefully and then turned back to face them. “Everything beyond what was crystallized kept going and eventually caused that second collision. But this is still helpful information.”
“So then, if we did something like that to a colliding pair of timelines,” Sunset said, “where we crystallize the one that’s about to be hit, there won’t be any damage to either of them. Maybe we’ll even stop the timeline that was moving, too.”
Crystal nodded and then turned and walked through her own barrier. She ruffled her wings at the sight of the gales above and coursed some idle magic into her horn.
Twilight slapped the ground. “And, if we did that everywhere we need to, that would solve the entire collision problem.”
“Yeah,” Sunset said.
Twilight giggled and shook her head. “Gosh, Sunset, you’ve been really on the ball with all of this. I’m impressed!”
Sunset blushed and rubbed the back of her head. “Yeah, well, dealing with the Nameless was really good practice.”
Crystal kept watching the gale in silence and then she spotted a long, rod-like object come flying out of it. Her eyes tracked it as it arced toward them, and just as it was about to lance through them, Crystal shot into the air. She grabbed the staff mid-flight as she barreled right toward the storm. At the same time, she shot a bolt of magic out of her horn which tore a gigantic hole through the cyclone. Much of the winds around it immediately evaporated or otherwise tore themselves apart.
And then Crystal disappeared into some of the remaining bits of cloud with the staff still tucked within her forelegs. A few seconds went by, during which the remaining clouds calmed down and quit circulating.
At that point, the barrier which had been around the four of them melted. Crystal appeared in the same instant, now empty-hooved.
“I agree,” she said. “I think that’s a really good plan. But…”
“Yeah yeah,” Starlight groaned and rolled her eyes, “details and all that stuff.”
“Right. We don’t have to block it out right this second. But…” Crystal frowned and let out a sigh. “I’m already trying to think of how high we’d have to make such a wall; how much time I’d have to crystallize.”
“If we have to make the wall,” Sunset replied.
Crystal nodded and said, “I might have some ideas. But, also, I’m concerned about the astronomical amount of timelines that I’d have to work this method on.”
* * *
Crystal magically levitated herself a few meters above the library floor. She faced the ceiling, watching for her reflection in any of its tessellated shapes.
“It’s a lot of ground to cover, and if the affected area is spreading faster than we can contain it,” Twilight said, pausing to sip on her tea, “then we have a major problem.”
“That’s right. And I don’t know how fast these disastrous effects are proliferating. I could see them, of course, but keeping up is another matter.” Crystal shook her head and bit into a banana.
“It would probably be for the best if we could save the entire multiverse in one fell swoop,” Twilight agreed.
“Okay, then maybe once we know what timelines we have to hit,” Sunset said, “maybe Crystal can just quickly travel between them all and do whatever she needs to do to set them up?”
Crystal shook her head. “No, that will not work. There’s a tiny amount of latency with the travel ability. In the time it takes me to travel to some timeline, place an object there, and leave, some other set of timelines could start collapsing.”
Sunset grimaced and lay down on her cushion.
Starlight turned her attention to Crystal. “Say, you can make other things travel between timelines with you. That’s how you’ve been bringing us along.”
Crystal nodded and took another bite from her banana.
“But is it possible for you to send something to some other timeline without you yourself going anywhere?” Starlight asked.
Crystal blinked and then flipped over to face Starlight. “I think… theoretically…”
Chrysalis buzzed her wings as she stood up. “If you did that, you would be able to do this in…” She angled toward Twilight and said, “Hmmm, how was it that you put it? Oh, yes, do it ‘in one fell swoop.’ That would be marvelous, indeed.”
Crystal chuckled. “Agreed. I actually see that to be a viable method. There are just a couple of issues with it… I think.”
Sunset groaned. “What?”
“Obviously, I’m not going to know exactly what we need to do until I can get a reading on those holes,” Crystal said, “but it could very well be that we’ll have to do some additional work in some of those timelines.”
“That isn’t an issue because you already proved that you can sustain a spell across multiple timelines,” Twilight said. “This would just be a matter of sending a premade spell into some other timeline and then casting it from here.”
Crystal nodded. “I suppose that is correct. That just leaves the other problem: actually hitting every target at once.”
Starlight threw her hooves into the air. “Just make a spell that automates all that. You could have it do all the travel ability and sub-spell management for you.”
Twilight raised an eyebrow and whirled to face Crystal. “And it could do it dynamically. I mean, we’d have to know the state of the multiverse at the moment you cast the spell anyway.”
Crystal was silent for a few moments. The magic coursing through her horn faded and she fell to the floor, landing on all four hooves. She glanced around and said, “I can do that. But it will be a complex spell. It’ll take some effort to make it.”
“Well, this never was going to be easy,” Chrysalis said with a roll of her eyes.
Twilight cracked a smile and stood up as well. “Well, if that is what we have to do, then we’ll do it. We’re with you, Crystal.”
“For sure,” Sunset agreed.
“Yeah,” Starlight said. “Crystal, we’ll need someplace to put this spell together.”
“I’m sure that I can think of something,” Crystal replied.
The others smiled in response.
Crystal scanned their faces again. She considered her friends, her team, the ponies that were about to embark on this project with her. “So, building a floor for those collapsing timelines to reduce the amount of debris, making a wall around those colliding timelines to keep those contained… And soon enough, we will know what to do with all the debris that’s floating out there.”
Crystal chuckled and nodded with approval. “It’s not a perfect plan… not yet… but it’s a plan nonetheless. Let’s do this.”