This story is a sequel to The Celestia Code

When the monsters created by the dark crystal engine escape their prison, it's up to Princess Twilight Sparkle to deal with them. She gets help and advice from Princess Luna, but things don't go as planned. In fact, when a pony who relies on logic and rationality tries to navigate the stormy seas of emotional entanglement while simultaneously saving Equestria from a horde of evil creatures intent on destroying everything they encounter, nothing goes as planned.
AUDIOBOOK by VisualPony
WARNING: Major spoilers in the comments.

Book 2 of the Alicorn Adventure series.

Goodreads Page
100% Approved by Twilight's Library!

The Badass Twilight tag applies more than ever, but please note the new tags.

This story is a fairly direct continuation of The Celestia Code. You might be able to follow it without having read The Celestia Code first, but it's better if you do.

The sequel is here: The Twilight Enigma

Most excellent pre-reading/editing done by the erudite AcademicPony and the dapper statoose!

This story is a sequel to The Cadenza Prophecies

Princess Flurry Heart inherited her mother's beauty and grace as well as her father's strength and bravery. The Empire couldn't hope for a better or more suitable heir to the Crystal Throne. Everypony in Equestria admires her and thinks she will be an ideal ruler.

They're wrong.

Young Flurry Heart has no interest at all in being a prim and proper princess, and would much rather have wild and dangerous adventures like her Aunt Twilight.

Book 5 of the Alicorn Adventure series.

This story is a sequel to The Luna Cypher

Twilight sets out to learn more of the ways of the world, and soon decides that the whole planet is disorganized, insanely dangerous, and desperately needs to be fixed. And she's just the mare to do it... with a little help from her friends.

Also, there are sky-pirates!

Book 3 of the Alicorn Adventure series.

A few extra, slice-o-life chapters are here: On the Rocks

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.

Book 1 of the Alicorn Adventure series.

AUDIOBOOK by VisualPony
Featured at the Royal Canterlot Library
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Goodreads Page (Courtesy of Facedeer)
Equestria Daily Page

WARNING: Major spoilers in the comments. Takes place several months after the end of season four. (Not a Da Vinci Code crossover, BTW!)

Do you see a dark tag? No, you don't. Not dark. Well, okay, there are a couple of dark-ish bits, but that's all. Not enough to warrant a tag. Speaking of tags, there really ought to be "Badass Twilight" and "Friendshipping" ones.

Sequels and side-stories (and more) can be found here Offprint and AO3, and a hardbound two-volume set of all that can be ordered from The Ministry of Image.

My editor for the first edition of this story was Gogito, and I can't thank him enough for all the hard work he did. My editor for the revised version was PresentPerfect, and he did a terrific job of getting the story into excellent shape.

A brave stallion goes on a quest to save the world by finding a lost princess in an enchanted forest. Things don't work out as he planned.

WARNING: Some spoilers in the comments. Also, a few mild spoilers for the Alicorn Adventure series, though it's not necessary to read those stories to understand this one.

Equestria Daily Page
Goodreads Page
Zabaware/AT&T Natural Voices "reading" by Modoc

For a human that ended up in an alien world full of talking ponies, you've been living a surprisingly boring life. Sure, you have friends and go on adventures and stuff, but you don't really have a "purpose" per se. At least, you didn't until about a month ago, when a "heinous villain" that had been turned to stone went missing from Canterlot. Now, there's a washed-up queen crashing in your basement and stealing your love.

If only you could get her to admit that she doesn't actually steal it from you.

Azurite isn't your normal sort of royal guard. Patrolling, protecting, and policing are fine for some ponies but they weren't for her after a routine call went sideways. Now, while struggling with the injury of her partner, she does her best to help others as a pony relations warrant officer in the palace. The palace, however, isn't quite the bastion of pony professionalism that she imagined and she soon finds her heart pulled in two different directions... toward a stallion and a mare.

Three of Hearts is an unconventional comedy-romance story that isn't afraid to take some of the most common tropes and turn them on their heads.

Quill & Blade Universe
Cover art designed and created for Three of Hearts by the super talented and ever sweet Painted Wave.

This story is a side story to Memoirs of a Royal Guard and begins years in advance of it.

Sunny Day doesn't take much seriously. As long as she makes a little money, spends time with her friends, and ends her evening with a cute pony she tends to be happy. The universe, however, seems to have other ideas as Sunny pushes to graduate from the prestigious School for Gifted Unicorns, understand her powerful magic, and start her life as an adult pony.

Quill & Blade Universe

This story is a sequel to Sunny's Days

Sunny Day is pretty happy with her life. She finally has the command she worked so hard for, and the view from atop her wall is amazing. It’s everything she wanted, but many ponies still view her as immature and wild. What more does she have to do to prove her worth and show them all she’s as serious as anypony else?

Elsewhere in Canterlot, Azurite used to be happy with her life. The tragedy that occurred during the recent Summer Sun Celebration changed everything, and now she’s struggling to get her hooves moving in the right direction again. All she wants to do is help other ponies like they’ve helped her, but her own fears keep getting in the way.

The paths before these two mares rarely touch, and yet wind closer together than either will ever know. Achieving their goals will ultimately rely on learning the same lesson: sometimes you just have to believe in yourself.

This story takes place between Sunny's Days and Three of Hearts. Knowledge of either is not required to enjoy the story but will add clarity.

Quill & Blade Universe

After Celestia takes her flying chariot to Ponyville to have an important talk with the new Princess Twilight Sparkle, she teleports back to Canterlot... leaving her charioteers behind. Unsure what else to do in the wake of this improbable, nay, highly unusual, nay, nay, impossible event, the two pegasi have a conversation that leads them to some startling revelations.