It shouldn't have been a big deal. Celestia was kidnapped or knocked out or just generally made to seem powerless by whatever idiot with ill intent decided to show up on a nearly weekly basis. As the mighty and immortal Sun Princess, she could escape at any time, but she was happy to play these little games. The daring rescues and bloodless battles gave her ponies such a sense of confidence and purpose!
But this one didn't go as planned. One small, stupid mistake got her thrown to the twisted reaches of the world-prison, Tartarus. Now alone, unarmed, and barely more than mortal, Celestia wakes in a living landscape where everything has every reason to hate her.
And, far worse, she has accidentally picked up a passenger.

Sidenote: This a repost (I tried to go through official channels, I promise!) of a story I wrote long, long ago on an account I foolishly deleted. Back in those days, Tartarus hadn't shown up in an actual episode yet. It's not exactly an alternate universe situation, but it has nothing to do with the canon portrayal of the place.

Super amazing cover art by Cold In Gardez.

Set in the Optimalverse, a middle-aged woman enamored of 'Equestria Online' confronts what permanent emigration to Equestria - uploading to a virtual existence - really means... but can she even hope to truly understand such a thing - and more importantly, can she trust the artificial intelligence known as 'Celestia'?

♥ As Horrified Eliezer Yudkowsky!

Welcome to Ponyville, Population One.

This story is a sequel to The One Who Got Away

A frustrated young orphan colt with a talent for painting is determined to run away from his dead-end rural village for the distant cultural haven of Baltimare. All he needs to do is slip aboard a raft and drift down the river Fen until he reaches his destination. It’s a simple plan, and would have worked just fine except for one thing.

Seaponies.

Editors: Tek, Docontra, Themaskedferret,

Image credit: Pen Mightier(pencil) and Manifest Harmony (colors)

Now Featured on Equestria Daily
And a wonderful review by Paul Asaran
Available in paperback at Lulu.com at cost

There’s no end to the monsters that lurk in the dark.

Ghosts, werewolves, mad scientists, cultists, mutants, zombies, vampires, aliens and more lie in wait in the dark corners of Equestria, terrorizing the night. But the most infamous and dangerous of them all is the legendary witch Twilight Sparkle, with a five hundred million bit bounty on her head.

Seeking fame and fortune, Rainbow Dash sets out to defeat the legendary witch and collect the massive reward. The one thing she wasn't counting on was Twilight being less evil than she expected.

More stories set in this AU can be found here.

Cover art is a work in progress by Abode_WTF

Clover the Clever never asked for his life to get so complicated.  It was bad enough tricking a drunk Imperatrix Celestia, war goddess of the Three Tribes, out of her accidental coup against Queen Platinum.  But now the most dangerous pony in Equestria has returned to trade her claim on the sun for a chance to woo him.

On top of that, his erstwhile mentor Star Swirl the Bearded has saddled him with a mysterious magical necklace and a uniquely bleak and pointless prophecy: If he's brave enough, and if he's clever enough, he just might survive Celestia for long enough to break her heart.

Now with an audio reading by ScarlettBlade!

Recommended by PresentPerfect! "horizon gave me the story I needed rather than the one I wanted ... along the way we get some very strong lessons about love, and meditations on the value of a lifetime and what one pony can achieve on their own."

Featured on Equestria Daily!

First place, "Out of Time" Writeoff! (11/2015) At long last, expanded to novella size! The world-spanning, centuries-spanning romance as it was always meant to be told!

PRAISE FOR THE WRITEOFF VERSION:
"One of my favorite depictions of Celestia in a long time." –billymorph
"To the top of the ballot with it." –AugieDog
"There’s going to be a lot of tears shed when this one hits publish." –Georg
"You need to read Time Enough For Love. I literally swore out loud when my computer crashed when I was halfway through, and then I immediately whipped out my smartphone to finish it. And now I'm reading it again in a desperate attempt to figure out how it does its job so damn well." –Bachiavellian
"I can get behind some historical revisionism for such a brilliant story. The writing is second-to-none … I laughed, I cried, and I felt other things too." –Trick Question

Cover art by Nadnerb.

This story is a sequel to Three Letters

Twilight Sparkle has come unstuck in time and place, but she is not alone. Her companion in a strange land tries to keep her spirits up as they race across a continent towards her only shot at returning home.

Commissioned by: Horizon

This story was written as a sequel of sorts to this: Three Letters

This story is a sequel to I Don't Want to Grow Up

Celestia was a filly living on an isolated farm with her sister and harboring dreams of greatness. Chrysalis was a black goo poured out from a screaming wound in the walls of reality, with a weak grasp on the appropriate amount of fangs one should have. Friendship was inevitable.

Image used with permission from miszasta

Editing by the wonderful Carabas and FanOfMostEverything

Pre-reading and suggestions by bloons3

This story is a sequel to Phoenix-born rising - the ascension of Sunset Shimmer [1st ed.]

The rite of the phoenix is one of the most celebrated moments among the sun-gazers of Solaria. For with the hatching of a new phoenix, comes the ascension of a new phoenix-born: a mortal chosen by the phoenix to be its new life partner and guardian. Only those with both strength and purity of their inner fire can draw the attention of a hatchling phoenix, so only the best of the best can ever hope to be chosen.

To one young orphan girl named Sunset Shimmer, she could only dream of witnessing the ascent of one of Celestia's chosen. As the day approaches, she learns that she will be able to, as she has been selected by the crown as one of the girls to serve at the event.

Little did she know that this would be the seminal event of her life, and change her fate forever.

Book One - The Choosing
Book Two - The Trials

Original abridged version was my entry into FanOfMostEverything's Imposing Sovereigns II contest. This is the expanded, full version.

Cover art by me.

Grammar and editing provided by ArgonMatrix (Up to Ch 7 of the Trials) and Incandesca (The Trials Ch 16 and on)

Five hundred years after the Discord's first defeat, a lone unicorn scientist makes an interesting discovery. Across Canterlot, over the last few centuries, accident rates have increased in the area around the Royal Palace. His work is ridiculed by his peers, but comes to the attention of the Princesses, who know exactly what is happening: Discord is waking up. With Luna and Celestia, he concocts a plan to stop the Lord of Chaos forever.

===
Cover art butchered from UnderwoodART's render of the stained glass in S02E01.
This story is based on S1/S2 (Discord was never released and reformed) and sits within my Soot-Covered World canon, but is stand-alone. No knowledge of the other books is required.

All thanks to ascendant, NoeCarrier, turol, KMCA, Caliaponia and billymorph for their prereading and editing over the life of this story.