In the most important day of Rainbow Dash's life, the only one of her friends that is missing is Pinkie Pie.

The only thing left of her is a letter.

A letter in which the pink pony poured all of her heart...

A letter in which there is everything she wished to say to the pegasus...and couldn't find the courage.

Mood Wings - Observations on Pegasus Body Language.

When Twilight Sparkle finds this book, she discovers an entirely new field of research. The secrets of pegasus wings lie before her, and she insists on making her own observations on the matter.

How?

Field research, of course.

Rarity's search for gemstones leads her to Sweet Apple Acres, and Applejack has no problem guiding her around the orchard. But when a freak storm strikes, the two ponies must race against the tempest to find shelter.

As the storm rages overhead, Applejack wrestles with the growing unrest within her heart regarding Rarity. And as events unfold, Rarity is forced to examine her own opinions and feelings towards her best friend.

(This is a RariJack shipfic, written per request/challenge for a friend.)

“Polyamory.”

Rainbow Dash blinked at Rarity. “Come again?”

“Polyamory. What you’re trying to build with Pinkie Pie and Fluttershy is called a polyamorous relationship."

“Okay,” said Rainbow Dash, “fine. So I know what it’s called. But what I really need to know is how I’m going to make it work!”

Featured on the Pony Fiction Vault, 05/11/12!
Sequel

Rainbow Dash returns from an evening in Cloudsdale to find Pinkie Pie in a dreadful state after a terrible nightmare. The pegasus tries her best to comfort her friend, but will it be enough?

Image by microgrid (http://microgrid.deviantart.com/).

Spanish translation by SPANIARD KIWI - https://www.deviantart.com/spaniard-kiwi/art/La-luz-en-la-oscuridad-970255243
Reading by Agent Fluffy - https://www.youtube.com/watch?v=BdVGfjmnsrM
Reading by Alchemystudent - https://www.youtube.com/watch?v=fcdJtTA5A14
Reading by AJ Earthbend - https://www.youtube.com/watch?v=Nw_sIt1PfQ8
Review (sort of) by Changeling Number 32 - https://www.youtube.com/watch?v=gEb_xv9eQdo

My Little Pony: Friendship is Magic and its characters are owned by Lauren Faust and Hasbro. Characters are used without permission but with the greatest respect.

Rainbow Dash is having an awful, terrible, no-good very bad day. Nothing seems to be going right! Pinkie Pie, being a dutiful friend, steps in to whisk her friend away to a one-day-only shop called the Make Me Better Boutique. But will she be able to cheer up her best friend? And will that cheering up lead to something ... more?

(Femshipping, but no wilder than a G/PG movie. Fun fact: This was one of the first (possibly the first?) fics that explored the idea of 'wing boners.')

Applejack finds herself having to take a drunken Rarity back to her house. All does not go as planned.