In an effort to keep her mind occupied, Twilight Sparkle decides to delve once again into the grand mysteries of Pinkie Pie. This time, Twilight's focus is on her claims of growing up on a rock farm: like so many things related to Pinkie Pie, the idea that somepony could grow rocks as an agricultural product makes absolutely no sense. However, the investigation eventually leads Twilight to a rather... surprising discovery.

This is the first story in The Petriculture Cycle.

Artwork by Page Turner. Now with a TV Tropes page.

Twilight has something she needs to tell Princess Celestia--something that means a chance at getting everything she's ever wanted, or of losing everything she's ever had.

Something so terrifying that the only way she could say it was in a letter...and so wonderful that she had the courage to send it.

(Thanks to Cenit V for the cover!)

Distance can drive us apart. It can also bring us closer together.

After all is said and done, and the ponies have gone their separate ways, the only way they have to keep in touch is through letters.

Original Equestria Daily post is here
Russian translation
Chinese translation
Polish translation
Spanish translation

Now with music and audiobook

To save her sister and her faithful student, Celestia herself must travel into the ancient tunnels beneath the ruined castle in the Everfree Forest. She, and the guards who accompany her, must face the dark, twisting corridors. Still, what was Luna and Twilight's purpose at the old castle? Why were they unable to return of their own accord?

And what watches Celestia from beyond the light's edge?

Celestia likes her routine. Tax reforms, grants, laws and construction projects are all a princess needs to be content.

It's just her luck that for Pinkie Pie, "content" is not nearly enough.

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

Scootaloo's life hasn't been the easiest. Being orphaned at a young age and brought up in the foster system came with its own set of challenges, not the least of which was a lack of older pegasi around to teach her how to fly. Fortunately, Rainbow Dash can help with that. With her honorary big sister taking a more active role in her life, Scootaloo learns much more about herself than just how to fly.

A story about love, family, and growing up.

Editing by Formerly Committed and Shellsh0cker.

Twilight and her five friends are transported during a botched spell, across dimensions to... Ponyville, Equestria? But not the same one that they knew. Sitting on a bench is Harpsy and Babar. The Doctoress avoids apples from an aspiring Applebuck. And in a library across town, six stallions join their forces as they try to decipher the appearance of filly look-alikes of themselves around Ponyville!

Many years after sending her beloved protege to Ponyville, unease sits heavily on Princess Celestia's heart as her relationship with Twilight Sparkle seems to have cooled despite all they've accomplished together. On the advice of her sister, Celestia sets out to investigate and resolve the lost connection with her most faithful student. What does it mean to be a Faithful Student...or a Princess of the Sun?

Earned a six-star rating on Equestria Daily and featured on its very own TVTropes page!.

The following transcripts are of a journal found in Ponyville on April 16th of this year. The last recorded contact with the town had been 3 days prior, on the 13th, when a team under orders from Princess Celestia was sent to look into several missing pony reports in the area. When another group of investigators were sent on the 16th, the town was found deserted. The journal’s owner is believed to be the princess’s personal student, Twilight Sparkle. None of the town’s inhabitants have been located in the weeks since.

Readings:
Nimbus Productions
Scribbler Productions

I highly recommend both of them.

A print version of all the stories in this series can be found here. (There is currently a printing error I am working to correct. This will be available again soon.)