Another day dawned over the united empire. Almost precisely ten years had passed since the Day of Union. Daylight, newly married to Mirage, had worked to pick up both of her mothers' legacies and succeded in doing so. Through diving into the Flow of Magic as Midnight had before her, she had gained great insight into the source of all magic, which in turn allowed her to funnel immense energy through her body, using her handiwork of runes to perhaps excel even Twilight Sparkle's power, creating glorious spells to the benefit of all.
And she had done everything she could to brighten up life for her and Mirage. After years of living together in harmony, linked through their endless love as well as their mutual connection to what remained of the hive mind, they had decided to take it a step further. She hadn't given Mirage the news yet, but their efforts had been successful fairly early on.
She had done her best to provide the best she could for all. The only problem was that not all seemed to want the same. One day, Mirage came to her, looking different than usual. "Do you happen to have some spell that could bring us both to Canterlot ASAP?" she said, without even bothering with a greeting.
"Magic Gateway could work. Why?" Daylight replied.
"Cast it. We need to go, quick." Mirage kept glancing out the window while waiting.
"What's the problem?" she insisted.
"The problem?" She dragged Daylight over to the window. The outside was significantly darker than it should be. "The Changelings, that's the problem!"
"Uhm, you do realise that-"
"Yes, I know, I'm half one, but that's not important. It's not in a true Changeling's nature to be sufficient. They always produce more drones. Sure Twilight set her back, but the Queen's been secretly breeding pure 'Lings and recreating the hive mind as it was. Now she's got an army that follows only her orders. Can you see that there might be a slight issue with that?"
"So, what do you propose?"
"Same thing we did last time. The Queen's here in Ponyville, I've seen her. We're gonna slip into Canterlot, find the spell your mother used, and recast it, once and for all this time."
"... sounds solid," Daylight said, then scribbled down a rune configuration on the ground and empowered it, creating a blazingly white doorway. "You go first." After Mirage, she stepped through herself, pleased to find that she'd hit her target in Queen Chrysalis' tower. "Okay, now, where did we find it?"
Mirage, who was already rummaging through the shelves, turned her head and said, "You don't remember? Good thing I do."
With their combined knowledge of for what to look, it was a matter of minutes until they had the book and scanned through the pages. "A-ha!" Daylight called and put her hoof on the right spell.
"Great, cast it. Maybe they're already underway, hurry!" Mirage kept looking around as if she was expecting troops to burst in any second.
"No volunteering?" the unicorn asked as she copied off the runes.
"Sorry, but I don't think we want to risk bad interactions between me and the spell. I'm not entirely a pony, remember."
"And I'm pregnant. Alright, here goes." Daylight pushed all of her energy into those runes laid out before her. It had once been her mother's signature spell, but it was not hers, so she had to cast it just normally, which meant an extreme expense. It wasn't working. She needed more power. She closed her eyes and concentrated. Surprisingly quick, the Flow came to her aid, empowering her with energy and allowing her to finish the spell before her wife could figure out the full meaning of what she had just said. The runes glowed brighter and brighter. Time itself seemed to slow down as her vision faded into something the likes of how the Magic Flow had been described to her. She cut the power supply, seeing as it was no longer required.
"So soon?" a voice said from behind her. She whirled around. It couldn't be Twilight, but it certainly looked like her. A pure white version of her that also was positively emitting sparks, anyway.
"Mother... what are you doing here?"
"Well, what can I say. I guess I just wanted to check back on my dear daughter. How her life went. How she got herself knocked up so soon after I departed. Oh, and how she'll save ponykind as I did." She laid a leg on Daylight's shoulders. "Come, we have some talking to do."
"What do I have to do now?"
"Essentially, you've got three choices right now. You could choose to empower this rune over here specifically to force everyone into synthesis," she said and pointed towards one particular rune in the configuration. "Honestly, I'd advise against that. I tried that. Didn't really work, did it. You could also go for this one," she pointed towards another, "to cause a wave of energy that'd fry every Changeling around. Literally every one of those little bugs. Once they're gone, they shall be no more threat, obviously, because there won't be any more to rebreed. The only problem would be that it's not selective. Intermediates would also die, like your little Mirage over here. Hell, even the littlun in your belly is partly Changeling. Would you really want to kill her?"
"Cut to the chase, what do you want me to do?"
"Hey, that's a valid option! I'm just giving out my opinion on it. Well, you could go with this rune over here and force the hive mind to become... you, essentially. No war can be fought without a general. If you were to take Chrysalis' position and force them to live in peace, that'd end this conflict."
"Hmm..." While she didn't let through much on the outside, Daylight was mentally calling out to her beloved for advice, which did not seem to go unnoticed by Twilight.
"She can't help you here. For the first time, you're actually alone. Choose!"
"I see. You are not my mother." She pushed the projection away from her.
"What? Don't talk nonsense."
"Mirage is always there for me. She never abandons me. That is, unless she's forced to. How naive I was. I should've realised this earlier. You are not my mother, neither a projection of her. Mirage isn't on her free will, but merely a puppet of you. You're asking me to change - enslave - everything, everyone. I can't make that decision. I won't."
"Filly, might I redirect your attention to what's important? Make a choice and end this!"
"No. I'm gonna end this war on my terms."
"Then you will die knowing that you failed to save everything you fought for."
"I fight for freedom. I fight for the right to choose our own fate, not be pawns ruled by some insect queen. And if I die," she looked up and straight into the eyes of her adversary, which showed a hint of fear, "I'll die knowing that I did everything I could to stop you. And I'll die free."
Apparently realising there was nothing to be gained for her here, the illusion turned, walked away, and faded out, presumably back into the Queen's mind. Slowly, the world came back to normal. She knew it was too late to turn back even if she wanted. She was exhausted. While she laid trying to recover some strength, Mirage approached her. She was lacking all of her usual tender care, replaced with pure menace.
"I know what you're up to, don't I?"
Mirage didn't answer in any way other than barring blank white fangs.
"I knew it. Be swift, and make sure to strike the foal as well. Show her mercy."