After a night of sleep (not that they had slept at all) the crew is at the citadel's cafeteria trying to find a way to restore their words when Dawn realizes something.
"You doesn't tell your story to us, Starlight."
"Yeah" agreed Sunset, "how did you end here?"
"I didn't was hit by a magical surge like you, I was trapped inside some kind of magical vortex."
"Cozy Glow"
All eyes turned to Daydream.
"She happened in my timeline too."
"Yeah," continued Starlight "this girl set up a plan to drain all Equestria's magic, using some magical artifacts."
Sunset reclined on her chair and crossed her arms.
"Twilight told me about her. In my universe, she had no success in this plan, but I guess she succeeded in yours."
"The last thing I remember is being dragged to a vortex that I suppose led to a void between dimensions, after that, I woke here on the citadel."
The room stays silent for some moments until Sunset spoke.
"Equestria was made of magic, all sentient beings had some kind of magic in them, so I'm supposing that when Cozy had success in her plan to drain all Equestria's magic to the void, it unstabilized, sending a blast of anti-magic over the world, which erased all that has some magic."
"And, since the void was a non-space between dimensions, it'd possible that the blast of non-magic may have spread across infinity realities, erasing all the parallels Equestrias, I suppose" concluded Dawn.
"But, why do we survive? we still have magic."
"That's a good question, Nova." said Daydream "This reminds me of a talk that I had with aunt Luna, eons ago. She said that couldn't see me in the dream realm, and after pondering for some time, we concluded that when the rainbow blast hit me, I was not only purified from all corrupted magic but somehow my entire being was rewritten, so magically speaking, I wasn't equestrian anymore, so because of that, I cannot go to the equestrian dream realm. So, since we aren't equestrian creatures anymore, we were spared from the magical purge."
"I guess this makes a lot of sense. Why wouldn't come to this conclusion earlier?"
"Our data was incomplete, Starlight. If wasn't for Hal's magic tracking algorithm, maybe would take some more years for us to find this answer." answered Crystal.
"Right, now that we know what probably caused all this fuss, so how do we fix this?" asked Nova
"The time spell. In your universe, you mastered Starswirl's time travel spell, right, Starlight?" asked Sunset
"Yeah, I used it to try to stop the girls from getting their cutie marks. But I already tried to go back in time and I was simply sent back to the present, it's like there's some kind of time travel lock, to prevent me from changing the past."
"Great, another dead-end."
"I guess not, Nova."
"What do you mean, Steve?"
"You still have the time coordinates in your mind, right, Starlight?"
"Yeah, but as I said, I can't go back."
"It's because you are locked outside from this point of the time, but what if you or none of us have to go to that coordinates? We can just go back to your world, in the present, place the harmony device there and then send it back to when you disappeared using your time coordinates."
"And since that moment is the point zero nexus, the explosion will spread to all realities, this could work." concluded Daydream with a smile.
"But we still have a problem, mom is the only harmony magic source available."
"Your pendant," said Daydream, "you still have it, Sunset?"
"Sure, but..." and something clicked on Sunset's mind "of course! I can have most of the harmony's magic, but my geode still has some too. And once we will use Starlight's coordinates to go to the exact moment when magic ceased from existing, we need only a little dash of magic to revert Cozy's spell effects. It's perfect!"
"When the harmony device will be ready?"
"Later today I guess, Crystal. Soon all of you will be with your friends again and will not even remember that all that happened."
"It won't work as you think"
All eyes turned to HAL.
"Care to explain why?" asked Sunset.
"Each of you came from a different timeline, and the event that happened on Starlight's one was the common nexus event from all of them. As you may know now, time isn't a straight line, is more like a yarn ball, with past, present, and future happening simultaneously, so if we try to change the past, we most likely will end up creating a new timeline not fixing the exiting ones."
"So, you are suggesting that we simply sit here, accepting that all our friends no longer exist? It is it?"
"Not really, Nova."
"So..."
"I think, Starlight, that we need to activate the harmony device in your timeline, right now, on the present, and once the harmony one's warp drive can drill across dimensions, we can hit all your timelines simultaneously, rebuilding your realities. For all the ones who disappeared, will be like nothing had happened, I suppose. No one, except us, will remember that the world once ended."
Sunset's watch beeps, and HAL (the ship one) speaks.
"Admiral Pie, the conversion of harmony one's warp drive is done."
"Thanks, HAL. Please, restore my default access level."
"Done. Your current access level is gamma, captain."
"It's the time of truth. Let's see if your theories will work." said Nova
"It will work."
"But, what if not?" asked Starlight to Daydream.
"So, what else we have left to lose?" answered Daydream with a tear in her eye.
The citadel's gate opens, and Harmony one drones carry the harmony device, placing it near the gate.
"Thanks, guys"
"At your service, captain." replied the drones in a chorus before leaving the citadel.
"All right, it's up to us now. Starlight, lead the way."
Starlight, Nova, Daydream, and Dawn cross the gate, arriving on Starlight's world.
"Right. I set up a 10-minute timer, it will give us enough time to put everypony on their world." Said, Dawn.
"Why can we just wait inside the citadel?"
"Well, Nova, you see." Said Daydream putting a wing over the unicorn's shoulder.
"Crystal, Sunset, and I were discussing some last-minute adjustments and concluded that our better shot would be having each one of us in their respective worlds, so when the magical blast created from her geode spreads across the multiverse, we will act as seeds. Our magic, combined with the explosion, will restart our worlds."
"Makes sense, I guess."
"Nine minutes, girls" shouted Dawn.
Starlight walked and hugged Nova.
"It was a pleasure meeting you, Nova. I will never forget you. Now go, you have a world to save."
After waving her goodbyes to Starlight, they cross the gate again, and Nova and Daydream go back to their worlds.
"It's our time, Dawn. Ready to know my homeland?"
Before Dawn could respond, Sunrise stepped in front of them.
"Can I go with you? I have no world to go back."
"And who said that I would leave my little sister behind?" Said Dawn lifting Sunrise from the ground.
"Crystal..."
"Don't say nothing." said Crystal lifting a hoof and Sunset stop talking. "Just go, your friends wait for you, just as mine are waiting for me."
"It's not a goodbye, just a see you soon."
"Just get out my lawn" Said Crystal with a smile on her face.
Sunset, Dawn, and Sunrise cross the gates, for what they think is be the last time, and get onboard Harmony One.
"Welcome captain. Three minutes until the activation."
"Thank you, HAL. Begin takeoff procedures."
"As you wish, captain."
Sunset starts to walk down the landing ramp.
"Where are you going, mom?"
"I have to stay on the ground. HAL will take you and Sunrise over Ponyville. Don't worry, I'll be ok"
Dawn stays silent for some seconds.
"Fine, but if this plan goes wrong and you die, I will kill you."
"Awn, I love you too, honeybun."
Once on the ground, Sunset looks to her watch.
"Ten, nine, eight, seven, six, five, three, two, one, zero."
She feels warmth on her chest and sees that she is glowing. Soon, the ground around her starts to glow too and Sunset can seem like time is rolling back, debris turning buildings again, voices can be heard and ponies began to appear out of thin air.
Feeling her magic at full strength again, she levitates from the ground, seeing that the plan it's working. Seconds later, Equestria, at least until she can see, is back, like nothing ever happened.
After a short flight, she lands in front of friendship castle doors and knocks.
"Coming"
That voice filled her with joy. "Spike" she whispered.
"Sunset? What are you doing here, and in human form?"
She grabs and hugs him tightly.
"I've missed you, your scaly dragon."
"Spike, who's at the door?"
Twilight stops for some moments trying to process the scene.
"Sunset? What are you doing here? Not that isn't nice to see you, but..."
"Ah, shut up, Sparkle, and hug me."
Sunset grabs Twilight with her magic and hugs her.
"You have no idea how I've missed you"
"What? You visited me last week!"
Before Twilight could ask any further, a ship landed on the right side of the castle, and a human girl, a pony Sunset (?), and a robot are standing on the castle stairs.
"Did I miss something?" asked Twilight with not the slightest idea of what is happening.
"It's a long, story. How about some tea while I tell you everything?"