Set in the Equestria Girls universe!

When Twilight Sparkle (the scientist one, not the otherdimensional pony princess) predicts an oncoming magical calamity, it's up to Sunset Shimmer and her friends to stop it!

Now, they've got just two days to cover hundreds and hundreds of miles to get to exactly where the dimensional incursion is going to take place.

Good thing it's Spring Break. Road Trip!

This story is a sequel to Iron Hearts: Book 5 - Suffer Not the Alien to Live

An Age of Iron story.

Months have passed since the destruction of the Ork Space Hulk and the end of the war against the Waaagh that threatened to swallow the Centaur system and all its inhabitants.
The Iron Warriors' 38th Company is the absolute military power on the planet, and the survivors of the Lamman Sept and the ponies of Equestria stand with this mighty army of Chaos as they claim Centaur III as their own. Although the other nations of their world may not fully recognize the Company's dominance, it is no matter; the Iron Warriors make plans to return their cargo to the Eye of Terror and return to their eternal trade of piracy. The planet is secure, and can be shrouded by Warp storms at their whim. The natives are divided, weak, and anyway occupied fighting off the scattered Ork warbands. The military supremacy of Chaos is unchallenged, and bolstered by Equestria's reluctant, but hard-earned support.
As Ferrous Dominus expands its operations and the fleet performs its long-suffered duty, it seems nothing can stop the Iron Warriors and their equine allies. The denizens of this conflicted world start to hope that at last peace - if not a distinctly unstable and militaristic peace - has come, and they might start constructing a new, better future from the ruins of war.
But hope... is the first step on the road to disappointment.

(Dark humor warning; limited grimdark themes)
(Cover art by EZTP)
(Featured on 9/19/2015)

This story is a sequel to Iron Hearts: Book 4 - Emerald Dawn

An MLP/Warhammer 40K crossover, part 5.

With their plan established and put into motion, the 38th Company begins the long and unwieldy task of planetary defense, fueling the arcane energies that may yet unsteady the Empyrean and spare their fleet from an enemy without number or mercy. The inhabitants of Centaur III and even the abandoned aggressors help where they are able, but as their foes grow in number and destruction spreads across the planet, the war for the Centaur system has become a bloody race against time.
All the while, the grim culture of the Chaos marauders continues to mingle with the enlightened benevolence of their equine allies. Tempers fray and allegiances blur. But the die has been cast: Equestria and the Company will survive together, or be snuffed out together.
And even should they succeed, what future awaits these unlikeliest of friends?
For there is no peace among the stars. Only an eternity of carnage and slaughter, and the laughter of thirsting gods.

ALL THE EXPLOSIONS. JUST, ALL OF THEM.

(Cover art by Ahrimatt)
(This series now has its own TVtropes page!)
(This series is a contestant in the Tournament of Canterlot, a charity event to raise money for Syrian refugees! Go here for details and donations!)

This story is a sequel to Iron Hearts: Book 3 - The Sept Lamman

An MLP/Warhammer 40K crossover, part 4.

The Tau threat has passed. The fleet that once thought to sweep aside the tainted pirates of the 38th Company has fled the system. The Lamman Sept is broken, demoralized, leaderless...
... And victorious.

With Lamman's plan put into motion, an alien horde hurtles through the Warp toward the Centaur system, its soldiers without number and thirsting for violence. Equestria's heroes must find a way to stop them, or the entire planet will be overrun with ease and its inhabitants butchered. While they could afford some pretense of neutrality and disinterest in the fight between the Iron Warriors and the Tau, now it is their world that lay in the crosshairs of the foe. Ponykind will need help to survive, and they look to the forces of Chaos for aid. But is there any hope to be found in the darkness?

EXPLOSIONS ARE IMMINENT.

(Dark humor warning; mild grimdark)
(Cover Art by Ahrimatt)
(This series now has its own TVtropes page!)
(This series is a contestant in the Tournament of Canterlot, a charity event to raise money for Syrian refugees! Go here for details and donations!)

This story is a sequel to Iron Hearts: Book 2 - Ferrous Dominus

An MLP/Warhammer 40K crossover, part 3.

The formal negotiations between Equestria and the Iron Warriors have failed. Yet peace and even cooperation between the harmonious ponies and the corrupted militants blooms in the dark corners of Canterlot and the open streets of Ferrous Dominus. The Elements of Harmony are safe, trade flourishes, and cautious meetings grow into lasting friendships as an unsteady calm descends upon both forces.
Even the Tau threat seems to have mysteriously vanished as the Iron Warriors refuse to assault their hideouts and risk springing the traps of the Fire Caste.
But the Tau have not vanished. The Lamman Sept of the Tau Empire, the Fire Caste's hidden dagger, have come to grips with the slumbering giant looming over their doorstep and have moved forward into the final phases of their plan. Fleets ply the void, hunters stalk the orchards, and in the depths of the badlands a strange device is rapidly assembled for purposes unknown.
The Tau alone know that time is running out, and more than just the fate of Centaur III hangs in the balance.

SIGNIFICANT POSSIBILITY OF EXPLOSIONS.

(Dark humor warning; minor grimdark)
(Cover art by Ahrimatt)
(This series now has its own TVtropes page!)
(This series is a contestant in the Tournament of Canterlot, a charity event to raise money for Syrian refugees! Go here for details and donations!)

This story is a sequel to Iron Hearts: Book 1 - Planetfall

An MLP/Warhammer 40K Crossover, part 2.

Celestia has handed down her order. The Iron Warriors must be defeated and driven from the planet, lest the corrosive grip of Chaos infect their world. With great reluctance, Twilight and Company depart for the Iron Warriors fortress-factory in order to confront the Chaos Warsmith. However, in this mission it is not the might of the enemy that will be their greatest challenge, but their own burgeoning friendships with the admittedly less-than-saintly members of the 38th Company.
At least until the Iron Warriors actually consider them a threat. Then it's totally their military might that will prove to be their greatest challenge.
All the while, the Tau forces lick their wounds and plot their next move. They are far from defeated, and the Iron Warriors have little inkling as to the aliens' true purpose.

MORE EXPLOSIONS!!

(Dark humor warning; minor grimdark)
(Cover art by Nicholas Kay)
(This series now has its own TVtropes page!)
(This series is a contestant in the Tournament of Canterlot, a charity event to raise money for Syrian refugees! Go here for details and donations!)

An MLP/Warhammer 40K Crossover

The Iron Warriors 38th Company has landed in Equestria, entrenching themselves like a barbed hook. They hunt the aliens of the Tau Empire, intent on destruction and pillage.
A small squad is dispatched on a reconnaissance mission, only to find that there is intelligent life on this world besides the feuding space-farers.
Will these improbably adorable and friendly equine aliens turn the damned warriors of Chaos from their blood-soaked path, cleansing them of their dark legacy with the magic of friendship and harmony?

No.
No, that isn't happening.
EXPLOSIONS!!

(Dark humor warning; limited grimdark themes)
(Cover art by Nicholas Kay)
(This series now has its own TVtropes page!)
(This story is a contestant in the Tournament of Canterlot, a charity event to raise money for Syrian refugees! Go here for details and donations!)
(Featured on Equestria Daily 8/20/15 )

After a fleet of Separatist ships reactivates over Muunilinst at the end of the clone wars, a single Providence-class Dreadnaught escapes into unknown space in a randomized jump, and the Battle Droids on board meet everyone's favourite pony princess. Join Princess Twilight and friends as they try to make sense of the giant metal bathtubs from the sky and their strange occupants.

(Big thanks to my friend Dawny and my new editor Mine_Menace for editing this story for me, as well as Zaten for helping me proofread on later chapters)

WAIT, WHAT? I got featured? 05/27/2019
And apparently again 08/07/2019

This story is a sequel to Friendship is Grievous

The brutal Clone Wars have at last come to an end. The Separatists are no more, and from the ashes of the Galactic Republic, the Galactic Empire has emerged. Now, the ponies of Equestria must choose their path through a dark and terrible time.

TV Tropes page.

Cover art by Mix-up over at his his deviantart.

General Grievous, Supreme Commander of the Separatist Droid Army, conqueror of star systems, and slayer of Jedi. And... stranded on Equestria?

This can't end well.

TV Tropes page.

Now featuring a dramatic reading by LimeyPony!