When the Cutie Mark Crusaders dig up an ancient magical artifact, they unleash a spell on the town that allows everypony to see a "lie meter" floating above each other's heads. While attempting to solve the mystery, Twilight Sparkle has to analyze the tenuous balance between friendship and honesty. She doesn't like what she finds.

Based on a story idea conceived by theworstwriter
Written and posted with his permission

Derpy Hooves is secretly a changeling.

Nopony particularly notices, or cares.

(New 9/15/19: Spanish translation by Spaniard Kiwi! Thank you!)

This story is a sequel to Avocation

Life in Ponyville has been relatively quiet recently, which is somewhat surprising, given that the town's librarian tried to usurp the Equestrian throne only a few months ago. Aside from the appearance of a grumpy pegasus who set up shop as a cloudsmith, the aftermath is so unnoticeable that most ponies aren't even aware that the incident happened at all. Unfortunately, all that's about to change, thanks to the return of a certain revenge-obsessed showmare....

This is the fourth story in The Petriculture Cycle; reading the first three stories, which begin here, is highly recommended.

The artwork was provided by Page Turner, and the TV Tropes entry can be found here.

Daring Do cannot believe her luck when she is asked to help explore the most ancient tomb known to ponykind. But terrible danger awaits her, for beneath the earth rests something beyond equine understanding.

Warning: comments contain ending spoilers.

TVTropes page.
Alternate ending by Duplex Fields.
Archived in the Pony Fiction Vault.
Reviews:
One Man's Pony Ramblings
Louder Yay
PresentPerfect
The Royal Guard
Cleverpun's Critique Corner
The Goodfic Bin

At 3:15 AM, Adams woke me with a loud knock on my front door.
"Put your boots on," he said when I answered. "There's a biblical monster in my house."

* * *

A Visual Companion, by the author
Interview with the author, from the Royal Canterlot Library.
Audiobook by Robin Jacks and Wubcake.
Audiobook by Scribbler.
In-depth analysis by the Heroic Tales cast.
Literary Analysis by ScarletWeather.
Special thanks to GaryOak.
Reviews:
City of Doors
One Man's Pony Ramblings
PresentPerfect
Louder Yay
Between Lines
Bad Horse

Princess Celestia always knew that Twilight Sparkle was destined for great things, but she never revealed the source of that knowledge, not even to those closest to her. When the day of Twilight's true destiny finally arrives, can Celestia fulfill an ancient promise to save Equestia's past, present, and future, even it means saying goodbye to Twilight forever? How can Celestia refuse her mother's last wish?

Art by the inimitable Harwick

Nightmare Moon. Discord. Chrysalis. Sombra. We faced them all, together. Always we were together. Yet in one heart-stopping moment, I almost lost everything. They don't know how close it was, but I do. I alone know what almost happened. The truth. And the truth about the truth? It keeps me up at night.

And it terrifies me beyond anything else this world can offer.

But at least I have my friends to make it all feel better.

This story takes place directly after the events of "Wonderbolts Academy." First-person from Rainbow Dash's perspective.

Sister story to Scattered Dust. Not a required read to understand this, the stories will intertwine but are both stand-alones.

Featured on Equestria Daily, 1/7/2013!

Surgeon General's Warning: Here be feels. You have been warned.

Thanks to Carpe Diem for pre-reading!

Rarity discovers an old tradition involving the exchange of felt dolls as a sign of affection. This sparks a brilliant plan to play matchmaker with her friends, and between herself and Twilight.

But brilliant plans never go as expected, do they?

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Cover art by Acceleron
Chapter art by Ratofdrawn, Sketchyjackie, Dunnstar and fatalerror328!

This story is a sequel to Hard Reset

After the events of Hard Reset Twilight's life and mental well being are slowly returning to normal. Her recovery is cut short, though, when a letter arrives informing her that the time loop spell she cast is causing severe damage to space and time itself. In over her head, Twilight tries to summon anypony who will know how to fix it. The pony she gets is the last one she ever thought she would meet... and nothing like she expected him to be.

Available in Spanish thanks to dgs1993
Series TV Tropes page

A handful of pages recount a remarkable journey to Equestria by someone who sought only a little peace. The story continues in Justice, and concludes in Hope.