Princess Twilight Sparkle discovers a centuries-old mystery hidden in the Royal Archives. Her investigation leads through layer after layer of deception and misdirection, setting her hooves on a path that seems to be leading to a mysterious secret. Along the way, she learns that some friendships can be very, very strange.
The Celestia Code is a My Little Pony: Friendship Is Magic fanfiction written by iisaw. It has been featured on Equestria Daily and can be found here. It has a sequel, The Luna Cypher, which can be found here. A third entry, The Twilight Enigma, is also complete and can be found here. A fourth entry, The Skyla Pseudonym can be found here.
- Advanced Ancient Acropolis: The city ruins in the Badlands.
- Anachronic Order: Even aside from the In Medias Res moment, the early chapters jump back and forth between Twilight researching the hidden chamber in the Royal Palace, Twilight researching the journal at the university, and Twilight on the expedition to the badlands. By the end of the first act, the plot just focuses on the badlands and proceeds chronologically.
- Badass Bookworm: Twilight. In chapter 1 she tries to buy info from a dragon. It rears back to flame her. She sighs. And then uses percussive negotiations.
- Berserk Button: Threatening anyone Twilight likes. This includes known-only-a-few-chapters Jigsaw.
- Book Burning: Done by Twilight, of all ponies, to ensure Sombra's plan to kill Celestia doesn't happen.
- The Corruption: A massive crystal of dark magic fuels the Cornucopia. Its influence spreads hatred and madness to anyone who spends too long in the city. And when its power leaks out more quickly, it physically transforms changelings into monsters.
- Country Matters: Implied that Jigsaw says this, much to the chagrin of the horrified Twilight.
- The Dreaded: Twilight's first diplomatic letter to Chrysalis mentions this; she was angry (see Berserk Button above), and saying what she would have done had Jigsaw been hurt.[A]ll civilized beings would spit on the ground in utter disgust and horror at the mention of my name, for generations to come.
- Dreamworks Face: Just look at the story image!
- Drunk on the Dark Side: When the dark crystal breaks, Twilight saves her friends by absorbing all its dark magic. This immediately sends her on a power trip—still being Twilight Sparkle, she tries to impose order on the changeling hordes. Cshareee's Go Through Me moment pulls Twi back from her madness, and she vents the dark magic by blasting the uninhabited desert.
- Fantastic Racism: The ancient unicorns against the other pony races.
- Footnote Fever: Done frequently, to humorous effect.
- Go Through Me: Twilight, Drunk on the Dark Side, prepares to kill Queen Chrysalis for defying her. Cshareee steps between Chrysalis and Twilight, which shocks Twi back into sanity.
- Gilligan Cut: In the second chapter:There was just no way I was going to let Jigsaw assist me any further.
Jigsaw peered up over the boulder where she had taken cover during my "discussion" with the dragon, her eyes wide. "Holy Stars, Twilight! You smacked him around like he was just a misbehaving puppy!"
- Incompatible Orientation: Jigsaw falls head-over-heels in love with Twilight. Twilight isn't attracted to mares.
- In Medias Res: Starts in the middle with Twilight burning books, and the then the plot jumps back to the beginning of the story.
- Just Think of the Potential: The Cornucopia is a device that magically steals anything the user asks for. Sombra wrote quite a bit about the potential military applications—his notes are what convinces Twilight that the Cornucopia needs to be destroyed. Using the Cornucopia to murder (or massacre) would be as simple as shutting off the safety protocols and asking for, say, "Forty pegasus heads, please," or "One alicorn heart, please."
- Master Race: The ancient unicorns.
- Orbital Bombardment: Part of how Twilight convinces the Changelings to leave her and Jigsaw alone for a while. She sends a polite letter to Chrysalis (and makes clear she knows where she lives), then 'borrows' a little bit of Luna's territory. 'It's the velocity that counts. E-sub-k equals one-half m v-squared, after all, and I gave it a whole lot of v!'
- The Precursors: The ancient civilization in the Badlands.
- Replacement Love Interest: Jigsaw's relationship with the changeling Sesseressia starts off as this. Jigsaw starts dating while she's rebounding from Twilight turning her down, and she asks Sessie to take Twilight's form. Once things have cooled down, everypony agrees that that's rather creepy and unhealthy, so Sessie takes the shape of another unicorn who looks nothing like Twilight.
- S-Word Privileges: Jigsaw calls the ancient unicorn supremacists 'screwheads', shocking Twilight. Jigsaw insists that she's allowed to use that slur because she's a unicorn herself.
- Took a Level in Badass: Twilight. In terms of raw power, she isn't that much stronger than she is in canon, but she's a lot more confident, comfortable, and creative with using that power. And with a few years of being a princess under her belt, she's shaping up to be a pretty sharp politician, as well.
- You Said You Would Let Me Go: Twilight promised to let a changeling she captured go if said changeling took her to a captured friend. Once the friend is released, Twilight then turns—slowly—towards it. And walks slowly towards it. (Note that part of Twilight's 'persuasion' involved lava. Namely, making lava via its components, rock and heat.) Naturally, this is Twilight. She sends a sternly worded memo.