One by one, Twilight and her friends must come to terms with the consequences of being the Elements of Harmony.

These stories take place in the intervening time between Season One and Season Two,
with the exception of Ditzy Doo: Muffins, which takes place early in Season One.

The series continues in the sequel, Secrets and Lies.

Pony Psychology has a TV Tropes Page.

Set in the far future after Celestia and Luna mysteriously vanished and the sun and moon froze in the sky, Antipodes is the story of two ponies thrust out into the harsh new world on an adventure to uncover what happened to the world so long ago.

(I wrote this when I was 17. it's pretty rough in places, but i think the basic ideas i had here were pretty cool. it's got a good skeleton)

Spanish translation here: https://www.deviantart.com/spaniard-kiwi/art/Antipodas-1-3-953524835

Luna discovers something hidden from Celestia for twenty years, now, with emotions running high, she enlists the help of the Mane 6... but what seemed to be a single mystery, soon reveals a darker and much more complicated plot that will soon decide the fate of Equestria.

Check out the Empty Room TV Tropes Page (Warning: Spoilers!)

Revised chapters edits and proofing (with many thanks) by: lammy, Trevor, Nick Nack, Fifth Alicorn