Once

It had all started with a lapse.  One in judgement.  After the Canterlot Wedding, who would believe her?  She was just so, so stupid.  She was going to die.

"Luna, I want to tell you something." Princess Celestia asked her sister, Luna.

"What?  I am going to bed; dear sister; I do not have time for jokes."

"This isn't a joke."  Then she did it.  The stupidest thing she had ever done.

She shown herself - her true self - a sleek black body with rainbow carapace and a orange mane.  Oh, how stupid she had been, she had learned a thousand times that ponies were stubborn.  How she wrapped that action with every ounce of regret she had.  Regret, it smelled of skunk and tasted of vile things that most animals would never have put upon their tastebuds.

Luna stared in blank shock for a moment, then her face broke into a snarl of rage.

"WHAT HAS THOU DONE TO MY SISTER?!"

"Luna, please -"  Her voice sounded a little different, but similar to the caring tone she had mastered a thousand years ago.

"DO NOT CALL ME LUNA, MONSTER! WHERE HAS THOU PLACED MY SISTER?!"

"Luna, I am your -"

She used a holey hoof outfitted with a silver chain and rubbed away the tears from her eyes.   Images of her sister angry; so angry she could taste it; like fire.

Why did that have to happen to me?  she thought.  I meant the best, Luna,, but I should have just told you earlier.  I should have!  Oh, the bitter misfortunes fate has placed upon us.  She heard her real voice echoing in her head - I am Celestia, I am Celestia, please, won't you listen?

She started thinking about her student, no, faithful student, and she sniffled.  A little sniffle, with controlled grace, but also bearing the burden of a million regrets.   A million regrets, Celestia thought, maybe more.  The little ponies, they don't deserve this, why?

Another sniffle broke the air.  It had been so many years.  What was her real name?  She had long since forgotten.  She had just sank into the position of Celestia, after the dying filly told her, "do me.  Please, little changeling."

"Okay, tell me where Celestia is!  NOW!"  Luna gestured to the torture racks.  They hadn't been used for a thousand years.  She was trapped.  If she told Luna the truth, she would have to face those.  If she told a lie, she could escape.

No, she would not tell a lie.  She had told too many.  "Here.  Sitting in front of you."  Somehow, Luna's anger intensified.  Maybe it could wash away the pain.  She felt herself placed onto the rack, shackles snapping closed around her limbs.  She saw a sight she hoped she would never see - Luna, her beloved Lulu, turning the cranks.  Nothing happened for a moment, other than the squeaking of the crank.

Then, it started.  She screamed - the machine's knives cut into her, breaking slots in the chitin and spilling green blood.  Celestia felt like it was making her catch on fire.  She felt happiness steaming in great mounds from Luna, barely sensible over the agony.   The knives started to cut deeper, piercing her intestines, and blinding her eyes.  It then paused.

"TELL ME, YOU GREAT MONSTER!"

"Luna, I am -"

"DO NOT TRY TO TRICK ME!   I KNOW HOW YOU SCUM WORK!"

It echoed in her head.   Scum, scum, scum.  Her sister, her own sister, called her scum.  A whole new dimension of tears splashed down her face.

She thought of Twilight Sparkle.  She loved the lavender filly - now alicorn - so much, she could get a full belly on it.  She only hoped the beautiful studious alicorn would fare well after her death.

Memory after happy memory poured into her mind.  Playing hide-and-seek with the little ball of energy, and teaching her advanced magic.  With every little memory only brought little tears.  But she must accept her fate - she was to die.  The little alicorn could do it.  But she, she only meant for the best!   She only wanted to help!  Why?!

And Book Shelf, the Royal Guard, the pride she felt.  But Cadence and Twilight and Luna could do it!  Oh, why?!

Why, why, why.   Celestia kept asking, her blindness not helping.

All the thing she loved.  Luna.  Cadence.  Twilight.  She saw the filly with glasses on Nerd Day,  the pink pegasus hugging her white colt friend, Luna snapping photos with her.  "Beach, it is the greawest inwention!"

Rough steps and little whispers creeped up.  Echoes of hoofsteps, on par with the clanking of their armor.

"Get up.  We'll bring you to the guillotine," said a gruff voice.  She knew it must have been the guard..

She stood up and the guard put a spear to her heart as she walked.  Pierce it, she thought.  It's broken already.  Her last tear rolled down her face.  She captured it, levitating it.    She was lead to the guillotine.  When she rested on the wooden contraption, she let it go and placed a charm on it.  She could hear the cheers of the crowd.  So this is how it ends, she thought.   My misfortunes.  Maybe one day, they will understand.   I will be liberated.

"For you, Luna," she placed it in the hooves of the dark blue executioner.  "My little ponies.  I wish you all good luck.   May I see you in heaven."

Then there was the swish of an axe.  Celestia was dead.  Luna grinned maniacally.

Luna took the crystallized tear and threw it onto the ground, demolishing it with her magic.

"Because you killed my sister, changeling."

"I'm so sorry, Tia!  I should have known!"