Much as the girls from Earth wanted the summer to last forever, it couldn't possibly. They only had a week left before their Senior year of classes started, after all.

The Twilights had amused themselves by getting Sunset to move heavy objects and generally fawning over the larger mare, in addition to furthering the understanding of the other in the fields of magic and technology.

Applejack had spent the summer practically cloistered at Sweet Apple Acres. Apple Bloom was enamored with her, and the summer’s productivity doubled with a second Applejack around.

The Rarities had spent roughly a week together, fussing over one another. Once the human Rarity had become acclimated to the use of magic, the pony Rarity had taken the opportunity to spend some time with her family and at her other shops abroad, secure in the knowledge that Carousel Boutique was in good hooves.

When the Pinkies met, there was an initial cringing moment where it was feared that the world might end- before they'd greeted one another as old friends. It was rare for either of them to be around somepony or someone who really got them, and they spent their time in characteristic good spirits. Even if the Dashes sometimes mixed them up and kissed the wrong one (or they mixed themselves up as a prank).

The Spikes had instantly gotten on like a house afire and had been absolutely inseparable, forming a bond that went further than scale-deep. They were Bros, and would be until the end of time, especially after Spike the Dog had been inducted into the Guy's Night group.

The Fluttershies had gotten along well. Too well, given that they were identical, which left everypony around them slightly uncomfortable.

The Crystal Prep girls had spent their days doing what some of them hadn't had opportunity or inclination to do in quite some time. To be teenage girls on holiday. Learning the abilities they gained as ponies, picnics in the park, swimming in the lake, exploring the neighboring countryside. Unmotivated by any ambition further than finding what would amuse next- or just spending a quiet rainy evening in the castle’s library between board games they'd found and ones that had been brought from their world.

All of them, except for Indigo Zap. The Washouts had spent a week in Ponyville before moving on, with Lightning Dust leaving a list of addresses where mail could reach her and rough dates upon which she'd be in each location. During that week, she’d been attached to Dusty’s hip.

The older mare had made a show of measuring Zap against her barrel before pulling a flat box out of her travel trunk. Light and airy lycra instead of the thick kevlar-padded jumpsuit worn during shows. A practice jumpsuit of her very own in a deep sable trimmed with neon green. Washed and pressed, but one of Lightning Dust’s. It wasn't a jacket, but her newly refound sister would be coming home with her, along with stories and pictures as well as souvenirs for their human mother.

With Dusty flying wingpony in the suit that clung to every inch, Indigo Zap flew Ghastly Gorge. She flew it until she could fly it cold, blindfolded. She flew it until her muscles screamed and her wings felt like they'd fall off. She flew until she felt her- the other her-, until she could arrive at the other end safe and sound without even a broken sweat.

Sometimes things work out.

Once it all had been explained, Indigo’s mother had cried and tentative plans had been formed to possibly venture to the other side of the mirror. To see her daughter fully grown and successful in a career she loved, even if she were a pony. And the agreement had to be made- someone, or rather somepony had to miss Indigo as much as Dusty was missed on this side.

When school started again for the year, the Crystal Prep girls were seated in the front quad, waiting for school to begin. Joking and reminiscing about their trip beyond the mirror. The sound of a powerful engine and the blat of a glasspacked tailpipe startled them and turned their attention as one to the student lot.

The throaty rumble died down as the big black Shadowbolt motorcycle was shut off, and the rider pulled off her helmet. Indigo Zap strode confidently towards them, the loosened Crystal Prep dress code altered further with thick-heeled knee-height boots beneath the regulation pleated skirt, and the boy’s shirt and tie she wore covered by a leather jacket. Spiked along the lapels, studded here and there, with a winged skull patch covering the back.

Sugarcoat piped up, raising a brow. “New bike, new jacket? That whole “changing your look to change everybody's perceptions of you” thing doesn't really work. At least not on you.”

Indigo fell loosely into the grass near her friends, supporting herself on her hands. “Sup to you too, Sugar. Nah, they're… they used to belong to Lightning Dust. My sister.”

As one, the other girls winced a little bit. It wasn't frequently brought up out of respect for their friend, but it was a known fact and none of them were really sure how to react- even with the existence of the other Lightning Dust. Except Lemon Zest, who as always was in her own little world of rock and roll.

Indigo started to say something about how it was fine, that the summer had gotten her over a lot, and that she'd gotten her sister back. But she was drowned out by the warning bell for homeroom, and settled for shaking her head with a smirk.

Sugarcoat paused at the front doors and Indigo shook her head, waving her on with a flick of her fingers. When she was certain she was alone, she pulled a book out of her bag that Princess Twilight had given her. The cover was a uniform black, with a lightning bolt painted on the front and stars scattering around the strike. Lightning Dust’s “Cutie Mark”. She snickered internally at the pony-name for a talent symbol.

She cracked it open and clicked a pen, closing her eyes for a moment.

To my Big Sister, and Best Friend.

I wrote to you a lot… after. I guess it's different now, since Princess Twilight says you'll actually be able to write back, if it works right. I hope your book made it to you safely, and I hope you're taking care of yourself. School starts today, and I'm honestly looking forward to it. I never did before, it used to just be another day.

Mom’s being typical Mom. After she found out about you she did a complete 180 on Equestria. We're working things out with Princess Twilight to take a trip across during the next break from school. She's got one of your headshots on her nightstand. Or you could drop by! Just write me a note in your copy and I'll come pick you up at the mirror.

Anyway, school’s about to start and I gotta dash to homeroom. Please be safe, and look after ~~our your~~ pony Mom for me. You can tell her whatever you want.

Seeya around, your best little sister;
Indigo Zap.

The images on the Omniscio faded, revealing the starfield behind them. Two ponies sat before the window, a low table set with recaff and a platter of cookies between them. The larger, a heliotrope alicorn whose wings blended to a dusky purple at the ends and whose mane and tail were crackling storms of tachyons and Cherenkov radiation, regarded her companion for the space of several timeless seconds.

The other was a Nocturne pegasus, tall and slender colored in shades of green. A tiny smirk showed her rather large fangs.

“You're a sap.”

The batpony drew herself up in mock affront, resting a hoof on her chest. “Me? Never.”

Her cheerful octarine eyes regarded her companion thoughtfully.

“I merely saw a dimensional pair lay out the challenge of a seven-ten split. I can't help that I flawlessly picked up the spare. More tea?”

Starlight Glimmer rolled her eyes and clicked the Omniscio to review another case. “Yes, please, Absinthe.”

Author's Note

And that's a wrap.
This story evolved from another one, the one I originally planned for Oroboro's "Journeys" contest that got killed by the Goliaths striding that battlefield and Scope Creep. It's being worked on, and the stories of the other girls will show up in more detail there.