Scootaloo's life has always been shrouded in mystery. She lives in her house in Ponyville alone. She often disappears with no explanation. And no one's ever seen her parents.
She keeps it that way deliberately. She likes her normal life in Ponyville, and has held on to it as much as she can.
However, a personal tragedy brings family responsibility down on her shoulders, and her life is about to spiral out of control.
Thankfully, she has quite a bit of help keeping both her lives stable - and separate - as much as possible...
...a dragon chef who can't make a salad without making it flambe...
...a cripplingly far-sighted ex-assassin hippogryph maid...
...a slim built minotaur gardener who is as innocent as he is unexpectedly strong...
...a mechanical golem head servant whose brain runs - badly - on hot tea...
...and one devil of a butler.

Edit: New Cover Art by ProfessorCatPro
Edit 2: New fan art by slyfoxcub.

[Complete! With TVTropes apparently!]
Also, apparently, an animated trailer.

In a world of brass and steam, Twilight Sparkle had thought she had made a life-changing discovery with the invention of the telescope. For better or worse, she was correct.

Now her discovery has not only changed her life, but the lives of those she seeks out in her desperate attempt to contact the only other creature as lonely as Twilight herself.

It all would have been much simpler, but it had to be the one Twilight could only call The Mare on the Moon.

Decidedly not within walking distance, then.

[Featured on EQD before story was meant to be submitted. 4/03/2015]

[Editing team: Southpaw, Wolfvenom, Maskedferret, SwanSong and BluePaladin42, without whom this story would be a fraction of its current state.]
[Special thanks to Novel-Idea for the updated cover]

Thanks to his sister, Shining Armor was running late. His drill sergeant asks him to explain why.

This is Shining Armor's 100% truthful recounting of events.

"Unicorns are wonderful!"
"Unicorns are fantastic!"
"Unicorns are marvelous!"
"Unicorns are glamorous!"
"Unicorns are enchanting!"
"Unicorns are terrific!"

They also like to twist words. What would happen if you asked what they really are, without the wordplay?

Unicorns provoke wonder. They create fantasies. They cause marvels. They project glamour. They weave enchantment. But most importantly, they spawn terror.

Massively A.U.

In a remote corner of the Solana Galaxy lies a backwater planet called Veldin. Nothing important ever happens there. Nothing exciting, either. Ratchet, a Lombax with no idea of his origins, is beginning to grow bored with his life, and dreams of excitement. He wishes on a falling star for some excitement to find its way into his life.

The falling star answers by crashing into his home in the form of a basket carrying a tiny creature with a horn, a pair of wings, and four hooves. The name on the basket reads "Twilight Sparkle".
----
Part of the PWNY-verse.

Edit: Now with cover art by the amazing G_Haze
Video Consultant/Technician: m2pt5 (he provides the infobot videos and similar.)

Edit: Game Timeline
Ratchet and Clank: Done
Going Commando: Done
Up Your Arsenal: Done
Deadlocked: Done.
Size Matters: Done.
Tools of Destruction: Done.
Quest for Booty: Done.
Crack in Time: Done.
All 4 One: Done.
Into the Nexus: Done.

Twilight Sparkle broke time when she got her cutie mark. Now Twilight and Sparkle are sisters from another time. Twilight is hailed as the potentially greatest light magician of all time, and already has a reputation as a hero by the time she goes to Ponyville. This isn't her story, not primarily.

Sparkle is an orphan - her dark magic killed her parents. She lives with her brother in Canterlot's industrial sector because they can't afford anything better. She can't leave either. She's a natural dark mage; while Sparkle won't go mad like Sombra, her reputation is hardly any better. Worse, the law doesn't see her as a good pony.

The fact that the dead don't stay dead around her, or that Thorn - Spike's double - is an undead, soul-eating abomination, are other matters altogether.

(Also has some Slice-of-Life, but fimfiction tags won't let me put it with Adventure.)

Has an ask blog to go with it: Ask Sparkle and Thorn.
Also has a TvTropes page: Split Second Tropes.

Featured on EQD.

Cover art by Swirling Line.