Twilight Sparkle was standing on her wife's balcony, watching the sunset, when she got the message from her brother. ::EMERGENCY! The Crystal Empire is under attack! I need help, and I need it now! Cadance can't hold the barrier for long!:: Twilight's head reeled, and the contact was severed abruptly, and painfully.
As Captain of the Royal Guard, Shining Armor was an incredibly gifted unicorn. His raw power might have exceeded hers, had she not been transformed into an alicorn recently. Her knowledge of spellcraft surpassed his, of course. Being in the Guard meant rarely having time to study, whereas Twilight's whole life had been spent nose-deep in books, from the time she was young. Between the pair of them, it should have been nigh-impossible to break the connection without their approval.
Shining's message spell was cut off with brilliant, blazing force, causing the fledgling Princess to cry out and drop to her knees, clutching her head. Her wife was at her side in less than a blink, holding her with tender care and concern.
"Twilight? What is it?" Princess Celestia asked her beloved. Her eyes searched the area for any sign of a threat, even as she set her inconceivably sharp mind to thinking of solutions to whatever problem was at hoof. Seeing no obvious threats, she turned most of her attention back to the mare who had opened her heart from the shell she'd built around herself. Twilight was recovering from the shock, shaking her head dazedly.
"Shining Armor...he's in trouble, and he needs my help!" Twilight cried, leaping to her hooves and flaring her wings as though to fly all the way to the Crystal Empire in one go. She gave an involuntary jerk when she felt Celestia's hoof on her shoulder. She looked up, feeling inexplicably guilty, and met the eyes of the elder Princess. She opened her mouth to apologize, but was cut off by a simple shake of the Solar Regent's head.
"He needs our help," Celestia said, turning towards the door to her chambers. "Guards!" Seconds after that single sharp word, two pegasi in golden armor stepped through the door, eyes searching intently for the reason their ruler had called them. Their eyes snapped back to Celestia when she spoke again. "Have my chariot prepared for a long journey. Princess Twilight and I travel to the Crystal Empire to aid Prince Shining Armor and Princess Cadance," she said. "Also, inform Princess Luna of the situation."
The two stallions saluted smartly and disappeared again.
Shining Armor stood on the battlements of the Crystal Palace, looking out at the looming darkness. His eyes narrowed, and he growled softly. "I'll get you for real, this time, monster," he muttered, turning back into the Palace and pointedly turning his back on the shadows. Stepping up to the side of the bed he shared with his wife, he leaned in and gave her a comforting nuzzle. "Don't worry, Caddy. I'm sure that Twily will be here, soon. And I bet she brings her friends again," he said, trying to mask his concern as he watched his wife deplete her magic to protect the Empire once again.
"We'll get him this time," she responded fiercely. Shining grinned, her fiery nature reminding him once again why he fell for her in the first place. He backed away, raising his hooves as though to ward off a blow.
"Easy there, killer," he said, chuckling. "Leave that to me and Twily. You just focus on making your magic last as long as you can...without hurting yourself, got it?" he asked, narrowing his eyes at her suspiciously. "I know you'll burn yourself out if you think it'll help...but this time, it won't, so stay safe, OK?" Cadance rolled her eyes at him.
"Yeah, yeah, I got it the first time, you overprotective dork," she teased, patting him with a hoof. Shining gave her that dopey smile she loved so much, and turned back to his duties. "Keep our ponies safe," she called after him. His reply was a simple grin back over his shoulder at her.
"Always."
Twilight watched in wonder as the chariot carrying herself and Celestia to the frozen North blasted across the sky. Celestia had cast a spell on the chariot before liftoff, making it lighter than a piece of paper. She had then similarly enchanted herself and Twilight, and enhanced the speed of the two pegasi pulling it. The results of said spellcasting were obvious to Twilight. They were, collectively, on the verge of breaking through the barrier that only Rainbow Dash had broken before.
"At this pace, we'll be in the Crystal Empire in a matter of hours," Celestia said in her ear, startling the junior Princess and making her give off an undignified squawk. She giggled softly, covering her mouth with a daintily placed hoof. "Easy, Twilight. We're not there yet, no cause for alarm," she said. Twilight gaped at her.
"No cause?! The whole Empire is in danger! My big brother needs help! For all I know, Queen Chrysalis has returned and taken control of him again, or worse!" she said, nearly breathless with worry. She took a few deep breaths, putting her hoof to her chest and pushing it away with each exhale. "It might even...it might even be..." she was cut off by Celestia's wing around her. She didn't notice the brief flicker of fear that passed across Celestia's features, or the hint of strain in her voice when she spoke.
"I'm sure it's nothing like that," she said softly, hugging the purple Princess against herself tightly. "Prepare for impact, Twilight," Celestia said, a light touch of Royal Canterlot Voice allowing her words to be heard clearly. Twilight spun around from where she'd been staring at the land passing beneath them, her eyes wide. She looked to and fro, searching for the source of the proposed impact, but saw nothing coming towards them in the air. Celestia pointed downward and to the front.
"We'll be there soon," she said, pointing out the Crystal Palace on the horizon. "And we're going to have a rather bumpy landing at this speed." Their relief at arriving so quickly was short-lived, though, when they caught a magical message that was so powerful, it seemed to be broadcast to the entire Crystal Empire.
::I have returned, subjects:: it said, somehow both painfully loud, and utterly silent. ::It is, after all, the divine right of a king to rule over his land::
Shining turned to Cadance, an expression of terror plain on his face. Elsewhere, Twilight and Celestia looked at one another fearfully. They spoke as one, Shining's tone filled with instinctive fear that drew Cadance's attention. She opened her mouth to ask him what was wrong, but he cut her off, and all four ponies said the same thing.
"King Sombra has returned."
Author's Note
OK, so...this idea popped into my head all at once, and I had to get it out. Let me know if you like it? This one will be at least a two-parter, with both parts also posted to The Twilestia Collab. 
EDIT: Did a little fixing of the pacing and such. Thoughts?
