She was gone.

Cadance wasn't sure how to process that, let alone handle it. Not that she was approaching things on an intellectual level. Sunset would have scolded her for that - she had been given a brain, she had an obligation to use it.

Of course, that thought evoked another choked sob from the Princess of Love, too.

Princess Celestia had delivered the news in the most dispassionate way: she had sent a dictated note while Cadance was being looked over by the Palace doctors for further injuries. It said little - and yet volumes.

Princess Mi Amore Cadenza:
While you were incapacitated, there was an incident involving Sunset Shimmer. To my regret and against my commands she acted in a foolhardy and dangerous manner, breaking into the castle's secure vaults and attempting to cast dark magic from one of the books held there. As a result, I ended her time as my student. Rather than deal with the consequences of her actions, Sunset Shimmer utilized an artifact contained in the vaults to escape to an alternate dimension. She will not be returning.

While I am certain you have many questions, I am unable to make time in my schedule at this moment and will be busy for the rest of tonight and most of the next day. We will meet for evening tea tomorrow after moonrise and can discuss the situation further at that time. Until then, you will rest and recuperate from your ordeal.

• Princess Celestia

'She will not be returning'. The finality of it clashed with the vagueness.

No other details were forthcoming, either. Nopony had seen Sunset since almost noon aside from a very brief period where she'd been spotted heading towards her rooms in the company of two guards. And the guards themselves were silent on the subject, only saying that this was a matter that should be brought up with Princess Celestia and that they couldn't speak about what few details they had. Even Spearhead - still recovering from his wounds - could only shake his head and say how sorry he was.

Cadance was also denied access to Sunset's room. She went there after the doctors released her (with a bottle of pills for her brutal headache), only to find the door magically sealed and doubly guarded. No admittance, direct orders from Princess Celestia.

And there was no seeking out the Princess for answers, either. Nopony was able to tell Cadance where the elder alicorn had gone - not that they didn't know, but they had been ordered not to inform Cadance. And with the additional command that she go rest, the situation was being handled.

So that was it. Sunset was gone and there were no answers. Cadance - head still pounding and heart shattered - shuffled through the halls back to her room and follow orders. Several of the Palace staff paused as the younger princess went by, asking if they could assist her. Cadance had no answer for them, merely shaking her head and blindly walking on.

When she finally reached her room, Cadance shut the door and collapsed into bed. This proved to be a mistake. Face-down in the pillows, she got a nose full of a particular mix of scents: cherries and woodsmoke.

It occurred to Cadance that, even if she prevented the maids from changing her bedding and washing the pillowcase, that scent would naturally fade in a day or two and the last trace of Sunset would disappear.

Cadance was going to cry anyway - but that just made the tears flow harder.

Princess Celestia sipped her tea. There was no expression on her face - only the placid impassivity of a still pond.

Across the table, Princess Cadance was the opposite: her magic was sputtering in a way it hadn't in months, bobbling her teacup. Her eyes - red, tear-stained, and weary - could barely focus. But they kept flicking to Celestia's externally calm expression and her apparent complete lack of concern at what had happened the day before.

Cadance had spent the last twenty-four hours locked in her bedroom, inconsolable over Sunset's calamitous departure.

Celestia had hosted a diplomatic meeting with a faction of Kludgetowners that were rising to power in an effort to negotiate passage for the Guard to investigate Mount Aris, then held Day Court as per usual before ending things by attending a charity banquet staged by the Canterlot Philharmonic to benefit music programs for foals in underprivileged towns.

The teacup lifted again, wobbling in Cadance's magic. She could feel her emotions unbalancing her concentration - primarily the urge to fight as her grief receded and was replaced by anger. And her tired, tired eyes went to Celestia once more as a spike of fury shot through her heart.

Celestia lifted her own cup without the slightest flicker of emotion and took a sip.

Cadance opened her mouth, finally unable to hold back the raw wound of Sunset's absence and Celestia's complete neutrality on the subject.

"I believe I am irrevocably broken," said Princess Celestia as the teacup left her lips.

And Cadance stopped, emotions slamming into a brick wall.

"I see that now." The teacup set down with the lightest of sounds - porcelain just barely tapping porcelain. "I should never have taken on Sunset Shimmer as my personal student." An uncharacteristic dark chuckle snuck out of Celestia. "A manticore would have done a better job, I think."

"That's not true," Cadance retorted, more out of reaction than true feeling.

Celestia shook her head. "I took the best mare of her generation and ruin--" Her breath hitched with a hiccup. "And ruined her. Turned her into a vain, angry monster who chose to risk her own soul just to gain power and attention." Celestia took a deep breath, trying to set her head high and her neck straight again. (She succeeded only physically.) "Every lesson I thought I taught her, she learned the opposite. The more damning thing is that she was right and I've learned nothing over a thousand years. Almost every act she took echoes something my sister once did. I just..." Her words trailed away.

Then, in an uncharacteristic moment, one of her massive white wings swept the table clear with the force of a tornado. Utterly priceless, centuries-old china smashed against the wall as Princess Celestia bellowed in rage and sorrow.

Cadance didn't move as ancient instincts kicked in and fear froze her in place before a mighty predator.

Silence reigned for a few seconds save for the sounds of Celestia panting and of the dregs of tea dripping down the wall. Then she closed her eyes tightly and took singular deep breath.

"I am broken," she declared definitively. "I am the Sun. I am the Princess. I am Equestria. I am... I am not a pony anymore. I don't--I don't remember being one, either. And my Duty has cost me the first pony I cared about in centuries, just as it cost me Luna."

Suddenly, Celestia's eyes shot open and locked onto Cadance. Unfamiliar emotions boiled in them - things Cadance had never seen in Celestia before. Terror, being the foremost of them - followed shortly after by guilt and regret. "You should leave," she stated with firm desperation. "Today. Now. Forever. You need to go, Cadance, before I destroy you as well."

Cadance rose - shakily - and tried to step around the table to Celestia. Thoughts of a fight were gone, replaced by fear and concern. "No, I couldn't. I--"

Celestia moved, keeping the empty tea table between them. "I am as much a monster as I was when I ruined Luna. I am The Sun and everything I touch burns. Leave, Cadance. Leave while you still can. You are a creature of love and I have nothing left in my heart. I deserve this mockery of a life I've created."

"Never." Cadance's wing lashed out and toppled the table over, letting it smash against the floor and add to the broken mess. Celestia took a step backwards - but Cadance took two forwards instead. "I will not abandon a good pony who needs help. Not when we share the same grief." She took another step closer, and this time Celestia didn't retreat. "You need me right now. And... I need you, too." And Cadance reached out to hug her adoptive aunt.

For the first time in a thousand years, Celestia was embraced - wrapped in warm, fluffy wings that curled around her as her only peer in the universe held her close. And while the wings didn't quite reach far enough around to fully wrap her up? Neither had Luna's so long ago.

And Celestia - not the Princess but the pony - wept.

It took nearly an hour before the crying reached a manageable level and their embrace broke. Cadance's chest was soaked - not only from tears but a non-trivial amount of Celestial snot. Wiping it with a tea-soaked napkin was passable for the moment, but Cadance knew a hot shower was in her near future.

But not just yet.

The two mares sat beside the wrecked remains of the tea - shattered china and splintered wood scattered like leaves in autumn - as their respective emotions calmed.

Celestia broke the silence. "I... I apologize, Cadance." Her walls started to rebuild, pulling together into her usual calm, collected self. "That was unbecoming of--"

The most powerful teenager in Equestria cut her off. "Don't lie."

Silence returned.

"Don't lie," Cadance repeated, though this time more gently.

The walls stayed down.

Celestia smiled wryly. "I'm sorry. It's... habit." She let out a weighty sigh and cast her eyes at the broken mess around them. "Equestria has no need for a mewling foal who cannot cope with the pain of a single pony." And she stopped. Her face fell as she listened to her own words. "...I truly am a monster."

Once more, Cadance hugged her aunt. "You're hurt. Ponies do silly things when they're hurt." And they both knew that she wasn't talking only about Sunset.

"I don't do silly things. I do grotesque things." A shuddering sob rocked Celestia's body as she teetered on the edge of another breakdown.

"Nopony has a life without choices they regret," Cadance softly noted.

Which made Celestia laugh bitterly. "And after more than a dozen lifetimes, I regret more choices than there are stars."

Breaking the hug, Cadance pushed away enough to look Celestia in the eye. "Then let's start with making a good choice. How do we get Sunset back?"

For a moment, there was hope in Celestia's eyes - until Cadance said what the 'good choice' was. Then? Another collapse and Celestia sagged. "We can't."

Cadance steeled herself. "We can and we will."

Celestia shook her head, unable to look back. "Cadance, she's gone. The portal is closed. It could take years for it to reopen and it may not do so within a mortal's lifetime. Even if it does, she could be anywhere. It will be more than long enough for her to disappear. We would never be able to find her and Sunset won't come back on her own. Not after what happened. After what I said to her." Ancient, tired eyes pinched closed. "She might not even be able to return. I do not expect that world is a kind one."

Gently, Cadance wrapped her wing around Celestia again. "You can't be sure Sunset won't come home. She's..." A little smile played across her lips. "Good at defying expectations."

It was enough for Princess Celestia to snort and chuckle quietly. "She is that."

"We can't affect if Sunset comes home." Cadance gave her aunt a squeeze. "But we can decide what she comes home to."

Celestia finally looked up to Cadance and raised a questioning eyebrow.

Briefly Cadance hesitated, nerves on edge. But only briefly. "You said you're a monster. Do you want Sunset to return to that monster?"

Celestia was silent in shamed thought.

And Cadance went in for the kill. "Is the pony you are right now the one you want Luna to come back to."

Out of reaction - slave to tragic reality - Celestia corrected Cadance. "It is the Nightmare that will return, not--"

"Is the pony you are right now the one you want Luna to come back to." The statement was repeated, words firmer. No qualifiers. No mention of the monster that had loomed over Celestia's lonely life. Just the sacred name of her sister, barely spoken in centuries.

And with it, an implication that sang symphonies.

Celestsia had long since buried her last traces of hope - for her own sanity, she had no choice.

But Cadance had not. She was still full of hope and idealism and love. And she had learned a lesson of great importance from Sunset Shimmer: never give up. So her eyes were firmly on Celestia as she spoke. "Even if everything happens like you fear it will, do you want her last memory of you to be this? For her to find a monster?"

The younger alicorn glowed with the power of her mark - it hadn't saved Cadance's love, but here? There was another heart to mend. She needed no spell to do it - just a few words to remind Celestia of what was and let a spark of Love reignite centuries-extinguished embers.

With quiet determination, Celestia responded in a single word. "...No."

"Then we know where to start, Auntie."

Under her wing, Cadance could feel Celestia's spine straighten with newfound purpose.

Author's Note

One of the core inspirations of this story - of the arc for Celestia and Cadance - is a single line in My Farrier Lady, Sunspot by Georg. One where Celestia says this:

“Duty can be a terrible master. It can isolate you, turn you away from everypony who cares until you feel all alone in the world. If Cadence had not shaken me out of my mindless devotion to duty, if Twilight Sparkle had not given me hope, my duty would have blinded me to events, and I never would have regained my sister.”

That single line has stuck with me and was one of the founding inspirations for things.

Without Cadance, Celestia does not hope. She gives up on her sister. She is destined to fight and to fail. With her... Well. Sometimes a thing must be truly broken before it can be fixed.