With her eyes closed, Sunset thought about the fine line between happiness and despair. For a few short weeks, Sunset’s life had been amazing. She had great friends, a place to live, and the best girlfriend she could ever hope for. Even the small glitches in the journal didn’t bother her too much. At worst, they were like specks of dirt on a car headlight. Impossible to see in the bright light. But things had escalated so fast, and she remembered running down the hallways of Twilight’s castle, panicked, because everything was going wrong.
Her trip through the portal, rather than being instantaneous, had taken nearly a full minute. During that minute, she kept seeing flashes of both Equestria and the human world, constantly shifting into a pony and then back into human again. The experience was seared into her mind, and she was sure that there was a large number of nightmares in store for her. But her uncomfortable journey had only been the start.
Twilight could still see the portals flickering in and out of existence around the mirror. She caught glimpses of CHS, which was fortunately deserted since the school day was long over. When Sunset emerged from the portal, shaken and disoriented, Twilight’s fears had been confirmed. The magic that was keeping the portal open had begun to destabilize, most likely because of their increasingly frequent crossings. She remembered the reason Sunset had come over that day. They would watch the meteor shower together. But when the portal began to fail, all thoughts of a quiet evening had been swept away. As soon as Sunset had recovered from the trip between dimensions, Twilight had dragged her into the library, looking for a way to mitigate the effects of the destabilization.
Sunset had never read so many books so quickly before. Even now, lying on her couch, she could see the countless theories and formulae dancing in front of her mind’s eye. They’d been so optimistic, at first. Even though she’d been on shaky legs due to her odd journey, and even though she’d been alarmed by this turn of events, she hadn’t for a moment thought that the situation couldn’t be solved. But as the evening wore on, each and every book they opened said the same thing: the portal had to be sealed off, or the barrier between the dimensions would fail catastrophically, resulting in the annihilation of both worlds. She’d refused to believe it. She still refused to believe it.
Researching magical theories with Sunset was like something out of a dream to Twilight. Sure, Starlight was just as gifted in magic as Sunset was, but as much as Twilight enjoyed her company, it still wasn’t the same as with Sunset. At any other time, she would have been perfectly happy. But now, once again, the fate of the world hung in the balance. And this time, it didn’t look like her books were going to bring her the kind of solution that could bring a happy end. And with every new book reiterating what the others had already said, Twilight had begun to think about the best way to tell Sunset this. Several times, she’d started to speak, only to fall silent again when she saw Sunset’s determined eyes. Her girlfriend wasn’t giving up. She couldn’t either. But try as she might, she could not see a solution.
Sunset had known from the way Twilight looked at her that their efforts would be fruitless. And every time she saw that forlorn look, it had renewed her vigor in trying to come up with anything at all. Myriad ideas had run through her mind, unorthodox ways of forcing magic into a stable form, of restoring the mirror to its normal form. But she knew, deep within, that it was useless. No miracle was going to happen this time. If their worlds were to be saved, the portal needed to close. It was Twilight who came up with the initial idea of destroying the mirror, but Sunset had been the first to realize that just destroying the mirror wasn’t going to be enough. The other side would remain open, unless…unless it was forced closed from there.
Twilight’s horn sparked. She felt her stomach churning when she thought back to the moment Sunset had told her she needed to go back. Everything in her wanted to shout at her not to do it, to stay in Equestria, her true home. But the student of magic she was at her core knew that Sunset was right. The only way of doing this right was this. Sunset would use her Equestrian magic to contain and constrict the portal. Twilight would then use her magic to break the mirror. Everypony, everyone, would be safe. And along with the mirror, she’d break her own heart. And she’d known that, just like the mirror, her heart would remain broken.
Her breathing grew heavy as she recalled the final moments. Her eyes never left Sunset’s, even when they kissed for the last time. She’d forced herself not to cry then, and Sunset had done the same, and, ever the resolute one of them, Sunset had turned around and stepped through the portal. Twilight had waited, seen the flickering portals again, bigger and more detailed now, and without a shadow of a doubt, she knew that what she was about to do was the only thing that could be done. When her journal vibrated at Sunset’s signal, she destroyed the mirror.