“H-hi, Twilight.”
Cadence’s words hung in the air, stagnating and poisoning the atmosphere as Twilight stood motionless. Her eyes were wide in a light shade of panic, and she appeared to teeter on the precipice between bolting away and slamming the door in Cadence’s face.
Cadence found herself uncomfortable in her own skin, and her heart ached to see Twilight stare at her with fear and anger. A shifting mass of white behind Twilight caught Cadence’s attention, and she noticed Celestia standing atop a set of stairs that led higher into Twilight’s castle. Celestia looked nearly as shocked as Twilight, though there was no fear to be found in the depths of the Sun Queen. Cadence glared at her suspiciously, treacherous thoughts flashing through her mind.
“C-Cadence,” Twilight said in a near whisper, her voice catching.
Cadence nodded uneasily, forcing herself to look away from Celestia. Twilight was breaking out of her shell-shock state, and a parade of emotions shifted over her features in such rapid succession to be nearly indistinguishable. Twilight looked back over her withers, towards Celestia, then back to Cadence. She swallowed and shifted her hooves, then moved to the side of the door.
“Would you…would you like to come in?” she asked, her tone quickly whipped into civility. Cadence hid a wince, and bowed her head gratefully.
As she walked inside the Castle of Harmony, Cadence was strongly reminded of the Crystal Spire. The entire superstructure appeared to be a single flawless slab of crystal, each feature blending into the next, curves flowing into rigid struts and columns seamlessly. Even the stairs and bookcases seemed grown rather than built, a testament to the powerful magic that had born it forth.
It was a beautiful castle, and suited Twilight perfectly, but Cadence could not have cared less if she was standing in a collapsing mud hut in the middle of a burning forest. All her attention was on her wife, who was doing her best to school her features. She was largely successful, but Cadence knew her well enough to pick out fragments, ticks that Twilight could not entirely conceal. There was hurt, nervousness, and of course, anger.
From atop the stairs, Celestia cleared her throat. “I will give you two your privacy.” She looked directly at Twilight, making a point not to as much as glance at Cadence. “If you need me, I shall be in the library.”
Twilight nodded as Celestia turned and left in the direction from whence she had come, leaving the two of them alone in the foyer. They stood awkwardly for several moments before Twilight cleared her throat. “Would you like something to drink?”
Cadence opened her mouth to decline, but before the words could form on her lips she noticed the desperate, dry burning in her throat. Several days of hardly eating or drinking, exacerbated by the exertion of her rapid flight to Ponyville, had left her parched.
“Water, please,” she said with a nod. Twilight turned and led her through the castle’s first floor to an enormous kitchen, nearly as large as the Crystal Spire’s. Cadence hadn’t spent much time in the Castle of Harmony, and was taken by surprise by its grandeur.
“Wow, fancy. This is even nicer than the Canterlot Palace kitchens,” Cadence noted, trying to avoid another awkward silence with idle chitchat. Twilight gave a noncommittal nod as she filled a glass from the cupboard and passed it over. Cadence accepted it gratefully, and nearly emptied it in a single pull.
Her thirst momentarily quenched, Cadence looked up to find Twilight watching her expectantly. She realized that, after having flown a quarter of the way across Equestria and showing up at Twilight’s door unannounced after almost a week of no contact, she should probably say something.
This was it. This was her moment to save her marriage, to pull her own stupid flank out of the fire that she had stoked into a bellowing inferno. What she had done was indefensible, unacceptable, and unforgettable. But maybe, she hoped, it wasn’t unforgivable, if she could find the right words.
“Twilight, I…”
Cadence took a deep breath, and as she stared into Twilight’s beautiful eyes, she remembered every precious moment they had spent together. She remembered the day she arrived at Twilight Manor to foalsit a filly not much younger than she had been. She remembered the confusion she had felt, many years later, when she first realized her feelings for the younger mare who was like a sister to her. She remembered the excitement when she realized Twilight returned her affections, and the fear of asking her on a date. She remembered the bliss of their courtship, of late nights spent giggling together under a blanket in the Royal Library reading cheesy romance novels as cliche as they were poorly written. She remembered the joy when Twilight had pulled a small box previously concealed under her newly-acquired wings, and the deep kiss that followed when she had said yes, yes, yes.
She remembered their honeymoon, and the quiet nights they'd spent on a Bactrian beach, content to say nothing as their feathers and fur intermingled. She remembered the look of love Twilight had given her, heartfelt and sincere as any she had seen, reflecting the light of the stars and painting a portrait of such beauty to make the heavens weep.
She remembered all these things, and when she drew on herself to summon the words and express the boundless love she felt for the mare she had betrayed, none came.
“I’m sorry,” she said, her head falling in defeat.
There was a brief quiet, like the calm before a storm.
“Is that it?” Twilight asked unbelievably. “Is that all you have to say to me after what you did? That you’re sorry?”
Cadence backpedaled as Twilight advanced on her, the fire in her eyes a shade that could only be sparked by betrayal of the one closest to her heart. “Twilight, I—“
“No! You had sex with my brother, in our bed, and all you can think to say to me is that you’re sorry?!”
Cadence stammered wordlessly under the onslaught as she desperately struggled to put two words together in her own defense.
“Why? Just tell me why, Cadence!”
“Because it felt right!” Cadence bellowed, the sudden gale of her voice forcing Twilight back on her hooves.
Twilight and Cadence stared at each other, eyes wide as saucers, each realizing the implications of what she had said. As the meaning of Cadence’s words fell over her, Twilight’s rear legs collapsed, all her fury leaking out of her in an instant.
“I…” Cadence gathered her resolve, deciding that it was too late for her to turn back. Honesty would be her only refuge.
“Twilight,” she began softly, “I love you, I need you to know that. There is nopony else on this world that I treasure more than you.” She paused to ensure that Twilight was listening. Twilight’s disbelieving eyes were a painful confirmation that she was.
“There’s something wrong with me. I don’t know what it is, but it’s like this…this emptiness, right here,” she tapped her chest right above her heart. “It nags at me, all hours of the day, pulling at me every single moment."
Cadence took a deep breath as the instincts she had built to protect her secrets rebelled against her, but she pressed on. Twilight deserved the truth.
"It started right before our wedding, and at first I ignored it. I thought it was just pre-wedding jitters, and when I talked to Aun-to Princess Celestia, she told me the same. But then it just kept getting worse and worse and worse and I just couldn't stand it any more and I—“
Her breathing hitched, and she closed her eyes. “A few days before our wedding, I disguised myself in Canterlot, found a bar, and went home with a stallion,” she confessed, her head hung in shame.
“It made me feel a little better, at first. But then the feeling came back even stronger than before, and then there was the guilt about what I had done to you. I vowed I would never do something like that again, no matter what.” She glanced up for a brief moment, and saw that Twilight had a steady stream of tears sliding down her cheeks. She looked away quickly.
“Over the next few months, it kept getting worse, and I did my best to fight it. I would always come to you when I was struggling the hardest. I know you probably just thought it was part of the ‘honeymoon period,’ but I was trying so hard not to fall into those depths again, to be faithful to you.”
A wet spot appeared on the floor below her, and she realized that she had started crying as well.
“When I couldn’t stand it anymore, I had sex with one the maid's in the Canterlot Palace. I think that’s when the rumors started. Pretty soon after that, it happened again with a merchant here in the Empire. I slept with a couple of Princess Celestia’s guards, and then…and that’s when it started with Shining Armor.”
Cadence heard Twilight suppress a sob, but she didn’t look up. She didn’t feel like she even deserved to see Twilight after what she had done. She deserved a cage, a dingy cell without even a bucket or a musty pile of hay in the corner, but for the moment she owed Twilight the full explanation.
“When I was with Shining Armor, for the first time in so long, that horrible, empty feeling went away. With the others, it had been like putting a band-aid on a broken leg, but with him it was...it was different. I felt—” she very nearly said 'whole,' but even in her addled state Cadence realized what a poor choice of words that would have been, "I felt like myself again."
“H-his trips to ‘oversee the Imperial Guard’s retraining?’” Twilight accused, her voice thick with contempt. Cadence nodded, and when she heard hooves on crystal, she looked up to see Twilight standing and wiping her eyes.
“Twilight, I don’t know what is wrong with me, but I know one thing: I love you. You have to believe that, there is nopony else in the world I care for more than you.”
“Except my brother,” Twilight mumbled sadly, and Cadence recoiled as if struck.
“Please, Twilight," Cadence begged miserably, "I don't want to lose you. We can fix this together, but I need your help, and I'll do anything, just please, please give me a chance."
For a long, agonizing moment, it was quiet as Cadence silently pleaded for a miracle. Her special talent was helping bring ponies in love together, and yet she was reduced to a supplicant before the mare whose love mattered more to her than anything. All her skills, all her abilities, her intuitive knowledge on applying just the right pressure at just the right time to open one heart to another were to her in that moment a bag of sand in the desert. It left Cadence to watch, wait, and torment herself as Twilight sat away from her in silent judgement, face obscured from view.
“No,” Twilight whispered, and Cadence felt her soul crack. With a resolute shake of her head, Twilight set herself firmly on her hooves and repeated herself.
“No more, Cadence. If you want to be with my brother, that’s fine. But I will have no part of it.”
As Cadence watched, a dagger of ice-cold despair plunged into her heart, Twilight reached up and parted her mane, revealing the thin silver band around the base of her horn.
“Please, Twilight, wait just please don't—“
Twilight interrupted Cadence's pleading by deftly lifting the ring from around her horn. There was a brief flash of raspberry magic and a golden crown appeared beside her, a near copy of Cadence's own, the only noticeable difference being a pink starburst in place of a purple diamond.
“I, Princess Twilight Sparkle, hereby renounce my Imperial Crown, and dissolve our Union.”
Twilight carefully deposited the two objects at Cadence’s hooves, leaving Cadence to stare open-mouthed in horror. Twilight turned away as fresh tears began to fall from her eyes, and Cadence stood in mute anguish, her gaze torn between the jewelry and Twilight.
“I’d like you to leave now,” Twilight said without looking, her voice thick.
Cadence debated staying and trying to force the issue, to beg and plead for Twilight to forgive her, but, looking at Twilight and the regalia she had discarded, Cadence realized it was over. There was no hope for her, and there never had been.
Her vision clouded by tears, Cadence gathered the ring and crown in her magic and bolted out of the castle. The moment she met sunlight, her wings snapped out and launched her away from Ponyville, away from Twilight, away from everything.
She stopped on a hilltop just out of sight of Ponyville. Her legs failed her, unable to bear the slightest weight, and she collapsed to the ground clutching the silver ring tight against her chest. Her sobs echoed loudly across the land as she curled in on herself, and for hundreds of years afterwards local villagers would tell their children the story of the night the hills cried.