A horrible Cataclysm has turned all of Equestria into a Wasteland of barren ash and twilight desolation. The Sun and the Moon have been destroyed. Everypony has died--including Princesses Luna and Celestia. But one pony miraculously survives; she is a lone wanderer, the last of her kind, surrounded by menacing creatures that hate her. She navigates the Wastes in an airship and scavenges off the blighted landscape to keep herself alive.

Then one day she meets an old companion who grants her a gift, the chance to go back in time to the warm and sunny days of Ponyville, where her dead friends live in happiness. How far will the last pony venture into this joyous age of Equestria, even if she fully knows that there is no way to change the horrible fate of everypony she loves?

2013 Edition: Smaller Chapters, Better Grammar, and a Few New Scenes

(A shout-out to Vimbert, pre-reader and gentlecolt)

This isn't where I belong. I left all this behind years ago, moved on with my life. But a mare from my past brought me back, and now she won't let me go. So I'm stuck here, trying to make the best of it with ponies that don't understand me, don't even like me. But when something moves in the darkness, and when things go wrong in the cold, dead night, they'll turn to me to try to set things right.

Why? Because once a police pony, always a police pony.
~~
This is a spin-off story to 'Why am I Pinkie Pie?!', and will contain spoilers for that story, but it's not necessary to read that story to understand this one.
Cover art by the talented Conicer
Need more Cinnamon Swirl? Merlos the Mad wrote a fanfic of this story!

There is now a side-story: A Hard Day's Nightmare Night

"My name is Lyra Heartstrings, and you will not remember me. You won't even remember this conversation. Just like with everypony else I've ever met, everything I do or say will be forgotten. Every letter I've written will appear blank; every piece of evidence I've left behind will end up missing. I'm stuck here in Ponyville because of the same curse that has made me so forgettable. Still, that doesn't stop me from doing the one thing that I love: making music. If my melodies find their way into your heart, then there is still hope for me. If I can't prove that I exist, I can at least prove that my love for each and every one of you exists. Please, listen to my story, my symphony, for it is me."

Cover pic by Spotlight: askspotlight.tumblr.com

This story is a sequel to Steel Solstice

Continued in: My Little Apprentice: Apogee

Twilight Sparkle learns that the trust and goodwill of the Princess isn't always a good thing as she's given the trust of an important assignment. When that assignment turns out to be long-term, how will she handle taking care of a filly of her own? How will she handle this strange new filly, who proves to be much more than she appears. As a matter of fact, she seems to be from an entirely separate universe.

Meanwhile, Second Chance has kept only enough of her memories to know that she isn't what she should be. The wonderful world of Equestria has its own dangers, and she seems to have a knack for attracting trouble. The more of her memories return, the more she wishes she could just forget. But you can't forget when all of Equestria depends on you remembering.

Only one thing's for sure: The longer Twilight keeps this strange filly in her care, the stranger her own life will become, and things she thought she knew about Equestria will unravel before her eyes. Strange ancient devices, an eccentric mint unicorn and her so-called "Equestrian Precursor Society" are only the beginning for Twilight Sparkle as she begins a journey of her own. She too may wish she could simply forget. Unfortunately, it's too late for either of them.

It is the year 2038, and the Earth is slowly being consumed by a space-borne monstrosity dubbed the Black Tide, which is using nanotechnology to remake the planet into something hideously alien.

Erin Olsen works for Project Harmonics, humanity's last-ditch effort to find a new world before the Tide can wipe them out. But when that world is found, and it turns out to be occupied, Erin will need to find the courage to face the unknown in order to save the inhabitants of both worlds.

(Many thanks to Easteu for the fantastic cover image for this story!)

Now with its own TV Tropes page

There is now a follow-up to this story: Sunflower - Side Projects
Sequel: Project Sunflower: Harmony

The Princesses find an alien creature barely clinging to life at the scene of a terrifying crash. Can the Combined Power of the Elements of Harmony save it, or more importantly, should they save it? Will the arrival of this strange creature tear Equestria apart?

TV Tropes
https://tvtropes.org/pmwiki/pmwiki.php/FanFic/Article2