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Original Description:
 
Flurry Heart, Pound Cake, Pumpkin Cake, Misty Trail, and Dusk Fall follow Ambrose Apple through the magical barrier into Appleloosa As soon as they step in, the barrier closes back behind them.

AMBROSE: It’s an honor to meet you, Princess. Welcome to Appleloosa…

(He looks around, revealing a shabby ghost town. A tumbleweed drifts past them.)

It used to be more lively. Anyway, I’m Ambrose Apple. I’m guessing you’re here about Maredusa.

FLURRY: You do know!

AMBROSE: ‘Course I do. I been studying the return of Maredusa for years, but I only just figured she’d strike today. I tried to get to the palace to warn y’all, but by the time I made the connection, she’d already arrived here in Appleloosa.

POUNDS: She came here before she came to the Empire?

AMBROSE: ’Fraid so. She made stops all throughout Equestria before she came looking for you, Flurry. Our town woulda been as good as stone had my magic not come on back around.

MISTY: Your magic?

AMBROSE: Yes, ma’am.

MISTY: But you’re, like, an Earth Pony!

An Earth Pony stallion trots up to them, wearing a vest similar to Ambrose’s; his father, Braeburn.

BRAEBURN: Ambrose, who are these folks?

AMBROSE: Dad, meet Princess Flurry Heart and her friends.

The gang waves awkwardly. Braeburn’s face lights up.

BRAEBURN: Why it is, indeed! An honor to have you, Princess, ‘though I thought one of you royals woulda come to see my son’s magic sooner. You know, before Equestria was in crisis.

MISTY: I’m still confused; his magic? Am I the only one hearing this?

AMBROSE: Uhh…how ‘bout I take y’all to my place? We might have a lil’ more privacy there.

(He looks to his dad, obviously uncomfortable for his slight scorn toward Flurry. He turns to the others.)

Follow me.

They trot off, Ambrose leading the way to his house.

BRAEBURN: What if this magical shield thingy comes down? What do I do then?!

AMBROSE (calling back): Just call for me!

The group continues on toward Ambrose’s house. He opens the door and leads them to his room–which is more like a library. Shelves of books are stacked along the walls, with several of them piled up on his desk; some open and some not. The lighting is a bit dim, but the orange glow from the barrier shining through the window is creating a golden overcast.)

AMBROSE: Sorry it’s a bit cluttered, I wasn’t expecting company.

BRAEBURN (off-screen): AMBROSE! YOUR BARRIER’S ACTING FUNNY.

AMBROSE (calling): WHAT DO YOU MEAN, PA?!

BRAEBURN: IT LOOKS LIKE IT’S WAVING!

AMBROSE: THAT’S WHAT IT ALWAYS DOES!

BRAEBURN: YOU SURE?

Ambrose sighs and turns to his guests.

AMBROSE: One second–

(He starts to head toward the door but before he can get there, he teleports away in a flash of orange. He returns just a moment later.)

Sorry about that, my dad can sometimes be–

MISTY: What?!

All the others ponies are staring at him in awe.

PUMPKIN: You just did magic!

POUNDS: How’d you do that?

AMBROSE (sighing): I’m not exactly sure.

You see, ever since I was a filly, I’ve always been a bit different. I might be an Earth Pony, but magic has always been my passion. I’ve read every book by every great sorcerer ever written, studied every spell known to ponykind, researched and studied the innerworkings of all magical phenomena. It made me a bit of a pariah, and my dad constantly tried to get me to put the books down to help out with the farm–you know, what actually mattered. But then one day, the strangest thing happened. I was feeling lost and alone, confused about who I was and what my place in the world was supposed to be. I ran to the top of a hill and when I reached the summit, this brilliant comet blazed through the sky. It was unlike anything I’d ever seen, it was…magical. Before I knew it, I was surrounded by this sort of light blazin’ through me and for the first time, I felt like everything made sense. As soon as it left, I got this on my flank…

(He gestures to his cutie mark; the symbol of a comet.)

…and thought that was it. But as the days went by, I started noticing strange occurrences; little outbursts of magic from within me that didn’t make a lick of sense. I thought it was just my imagination, until an Ursa Minor came to terrorize the town and I vanished it with…a spell.

Ever since then, I’ve been able to do magic, but it’s not up to my control. It tends to happen whenever my emotions are heightened, and the spells usually correlate to it. My dad eventually told me my mom was a unicorn, I don’t know if that’s got anything to do with my ability to harness magic, but there ain’t nothing about Earth Ponies using unicorn magic in any of these books I’ve read. So, I still don’t know how…or why.

MISTY: You got your magic from a comet? We just read about this unicorn who used a comet to defeat Maredusa!

AMBROSE: Mm-hmm, Flashfire.

PUMPKIN: Do you think you’re connected?

AMBROSE: Maybe. I’m not sure.

Flurry squeaks in delight.

FLURRY: This is amazing! You’re a total inexplicable magical enigma! You have to meet my Aunt Twi…

She trails off, her eyes darkening. Ambrose notices.

AMBROSE: I take it things didn’t go too well for the princess.

DUSK: You could say that.

AMBROSE: Well, you’ve come to the right place. Hopefully.

(He gestures for the others to crowd around the desk and grabs a book from the pile with his mouth. He opens it in front of him and flips to find the page he wants.)

This is Starswirl the Bearded’s account of all the magical phenomena he encountered in Equestria before he died. He was mostly studying friendship in his final years so the journal’s pretty lighthearted…until the end.

Starswirl’s voice is heard, recounting the words Ambrose is reading from the journal.

STARSWIRL: “Entry 148. I’ve recently begun to feel a presence I’ve not felt since I was a colt, years before the inception of this land now known as Equestria. I fear Maredusa, the Mother of Monsters, has returned. Once vanquished by my mentor, the legendary Flashfire, she has been encased in stone for centuries. Perhaps it’s the return of the pillars, or the Magic of Friendship that’s spread throughout this land, but some powerful force has released her from imprisonment and there is no telling what horrors she might unleash.”

Entry 149. “Maredusa’s return seems increasingly evident, although most other ponies I try to inform seem to think I’ve gone senile. I believe she will be searching for my former students, Celestia and Luna–

FLURRY: Ooh! Love them. I mean, never met them–at least not that I remember–but what icons, am I right? I mean personally I’m more of a Princess Luna stan, I have this plush of her and one of her original…
(She trails off, noticing the others are staring at her. She laughs nervously.)
Ha ha. Uhh…you can keep going, Ambrose.

Ambrose nods and continues, Starswirl’s voice returning to recount the words.

STARSWIRL: “As Flashfire had informed me, only the life force of a true Alicorn can reverse the spell that took her magic away, and as I’ve known since I mentored them, Celestia and Luna are natural Alicorns; demigoddesses born of Queen Galaxia and King Cosmos. Although they’ve retired and have probably weakened from surrendering their posts, their magic is still immeasurable compared to any other being in Equestria. I have faith they will be able to defend themselves against whatever plan Maredusa might set in motion.”

Entry 150. “I fear I will not live long enough to fight against Maredusa’s incoming attack. Nopony has heard from Celestia and Luna since they’ve retired, I’ve tried to reach out to them but my letters have remained unreturned. Maredusa was turned to stone before the sisters were born–there is a chance she might not know of their existence–and if she’s done any research into the current Alicorn ruler, Princess Twilight Sparkle, she’ll quickly learn she’s not a true, natural-born Alicorn–no matter how talented she might be. I almost thought Maredusa’s plan would not be able to come to fruition, until I remembered the Crystal’s Empire’s littlest Princess; just a filly, but the first Alicorn to be born in Equestria. Although she’s mortal, the magic within her would be strong enough to undo Flashfire’s spell. I’ve sent word to the Crystal Empire’s rulers, Princess Cadance and Prince Shining Armor, but I know my efforts are likely futile. I can now only hope; for the fate of Equestria, and for the young Princess Flurry Heart.”

Ambrose closes the book. The others are silent for a moment.

MISTY: Celestia and Luna were demigods?!

FLURRY (shyly): Where’d you get this?

AMBROSE: It was in the Castle of the Two Sisters, I used to go there from time to time and take some of the books back to read.

FLURRY: Mm-hmm…

(She trails off, looking down.)

The others stare at her, unsure what to say.

POUNDS: You okay, Flurry?

She nods slowly

FLURRY: Oh, I’m more than okay…

(She brightens, stretching her wings and grinning.)

’Cause now we know what to do now! This must be why Spike sent the amulet, we have to find Celestia and Luna!

DUSK: Not to play Sombra’s advocate, but they’ve gone kinda awol.

FLURRY: My aunt just visited them at Silver Shoals. They’ve been pretty occupied enjoying their retirement, it’s probably why they weren’t able to get back to Starswirl.

PUMPKIN: Are you sure?

FLURRY: Of course I’m sure. Come on, everyone, let’s go find some demigods!

AMBROSE: Yee-haw! That’s more like it! Let’s get on the tr––

Before he can finish, a blast of orange magic emits from Ambrose and surrounds the group. They all vanish.

Wooo things are getting interesting, I hope y’all didn’t think I forgot about the two princesses in this gen. I plan to delve into their backstories more later on.
Finally think I got the gradient right in Flurry’s mane! It takes a little longer but I like the way it looks better.