Pinkie Pie has a strange tale to tell Twilight upon discovering a very strange coin among Pinkie's possessions.

Filly Pinkie Pie wonders why Princess Celestia is sad all the time, even on her birthday. Granny Pie tells her it's because long ago the princess had to destroy her sister Luna in order to save the world and no amount of time has lessened her sorrow. Little Pinkie Pie decides she is going to make Celestia happy with the best birthday present ever! Now all she has to do is build a time machine and go back and change the past...

Posted on EQD way back in 8/7/11 EQD For your Birthday, Princess.

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.

Stranded on a hostile, alien world, Twilight Sparkle and Rainbow Dash must depend on one another and a fellow alien castaway if they want to return home to Equestria.(originally published on FFN)

After witnessing a series of strange events Twilight Sparkle and friends search for answers, only to find themselves entangled in a war between two ancient races and a plot that could end all existence. Luckily, our heroes find help in the form of an eccentric brown pony with an impossible blue box.

A strange sickness has infected nearly everyone in Ponyville. It seems there is no hope for a cure - until Twilight stumbles across a strange blue box...

Big Macintosh seems like a simple pony who keeps to himself and doesn't say much, but there's more going on beneath the surface of this red stallion than it would seem at first glance. After his family urges him to go and make some friends in town, Big Macintosh finds himself meeting interesting ponies and discovering a whole world outside of his farm. But even with these new experiences, old memories and ghosts from the past resurface to haunt him. Big Macintosh finds himself confronted with something he thought he put behind him long ago…
(Originally written and posted to EqD in July 2011. Contains some minor plot elements and references to 'Opposites' which could possibly cause this story to be considered an "Alternate Universe" fic.)

Ziggy Stardust was never good at talking. A bouncer didn’t have to be. He wasn’t expecting that to change when he moved to ponyville. He wasn’t expecting the DJ either. Sometimes it just takes somepony else to get you started – all you need is a little feedback.

Luna attempts to distract herself from the same frustrations that she once let ruin her life.

Luna has just returned to Canterlot after a thousand years, eager to get back to her life as it once was. Better, in fact, now that the jealousy and bitterness that once ruled her heart has been banished from her. But as she tries to pick up the pieces of her former life and take up her position at Celestia's side, she finds that some things take longer than a millennium to change.

Over the year following her return, she must struggle with adapating to a society that dosen't know quite how to feel about her, and the demons that haunt her every hoofstep. Can she truly start anew, or will her new moon wane for good?

(Note: The first story I've ever written, cross-posted from ED. This was written wayyyyyy back in season one, and I don't have nearly the drive to update it in regards to current episodes, or to do a re-edit of some of the problems it has. The loss in accuracy shouldn't detract too much from the story itself. Besides, I can pride myself on having a decent peg on canon Luna before she was canon. :P )

There comes a time in every growing dragon's life when he has to go visit the doctors. Twilight just needs to show him who's boss... hijinks, as they say, ensue.