SF (canon species only; no humans) Ponies were magically and genetically engineered to be the perfect servitor race. They are powerful, adaptable, intelligent and completely under the control of their creators. A laboratory accident frees one such pony from her mental chains, but how can one mare save herself and the rest of her kind if she doesn't even know she's a slave?
This is not the Equestria you know and these are not your little ponies... not yet, anyway.

Tags: Adventure, Diamond Dogs, Gryphons, NO HUMANS (did I mention that already?)
Other tags: historical, mind control, Clarke's 3rd Law, excessive use of high energy physics, before they were famous.
Detailed review by PaulAsaran.
Cover art by endrome , used with permission.
Russian translation (partial -- 'unofficially' completed in the comments)
A Soot-Covered World, book 1.

Trixie has returned to the only life she hasn't failed at, rock farming. When her old rival comes to help her make amends, she's thrust into an adventure she doesn't want to be on, but it may be what she needs to reclaim her confidence as the Great and Powerful Trixie she once was.

By some cosmic happenstance, a young woman is transported to Equestria, and finds herself in a precarious situation. She's taking it in stride so far. Maybe because finding herself in an alien world and in an alien body is not the worst thing that's ever happened to her.

Some wounds, especially those of the soul, can take a long time to mend. What healing arts can the ponies of Equestria offer a scarred young woman? What can she offer them in return?

Timeline-wise takes place starts off in the later parts of season 4 but before the season finale. It also mentions events from the EG-movies and the comics, but neither of which are required watching/reading in order to understand this story.

Trigger-warnings:
- Human-turned-into-pony-
- Who's kind of okay with being a pony-
- And becomes friends with the Mane 6.
- Being a pony is pretty awesome.
- Has both slice of life and adventure.
- Equestria Girls happened.
- Like the source material, it has adventures.
- And Celestia is not a jerk.

Cover art by the extraordinarily skilled viwsrasputr.
The piece in particular has been uploaded here: https://derpibooru.org/1478347
Really cool art by Cyanjames2819. Also found here.
Leave a comment if you so desire. Simple praise also appreciated.