Keep in mind, a lot of this fanfiction will be going by the MLP FIM comics, ESPECIALLY this paticular story.

Previously in 'Equestria's worst enemy'
Equestria has suffered a great loss...
Sometime after the defeat of Lord Tirek, Princess Celestia and Luna had a vision of the return of Equestria's worst enemy,

'Enigma, the Lord of Deadly Chaos'
A Draconequus and brother to Discord, who is a much more formidable foe than Discord ever was, he enjoyed watching ponies suffer, and was responsible for the destruction of Celestia and Luna's home 'Alicornia'

When Celestia became aware of this, she asked Twilight Sparkle to find an ancient dragon who as of now goes by the name of 'Spine' as he was the only one who knew how to track down Celestia's older sister 'Queen Rota' who travels the world keeping the earth in rotation, thus her absence during most events, they had to find Rota, as she was the only one who might know how to restore the Elements from the events 'Princess Twilight Part II' Twilight set out to find him, leaving Rainbow Dash behind, to take care of an injured Sunset Shimmer, who fell through the mirror.

They found Spine in the Crystal Empire, running into Twilight's crush 'Flash Sentry' who decided to come with them,

Spine directed them to 'Flutter Valley' home to the Flutter Ponies, and the Alicorns 'Princess Sterling and Gold Lily' who rule over it.

They united with Rota, who explained to them that it was impossible to restore the Elements, which prompted Enigma to make a move...
It was revealed that since the events of 'Return of Harmony' he too had escaped his own stone prison, but had disappeared and hatched his own plan.

But upon hearing the elements are gone for good, he decided to make his move,

and that all his time, he had been hiding right under their noses as 'Flash Sentry'

After breaking Twilight Sparkle's heart, he unleashed acid rain on Ponyville, burning it the ground, the ponies however managed to escape into the Everfree,

After witnessing what they believed to be the death of Queen Rota, the remaining Mane 5, Spike, and Spine were transported via blue flame, just before Canterlot Castle came crumbling down on them.

And now the ponies awake, and discover a new world.

TRAPPED IN ANOTHER WORLD, ENTER PROFESSOR TIREK

We see the ponies, Spike, and Spine, appear in what resembles Canterlot Castle.

"Uuughh... what happened? anybody get the number of that truck?" Applejack asks sarcastically

Pinkie Pie groans "Does anybody know how we survived that? or should I just write off as a plot hole?"

Fluttershy gasps "WAIT A SECOND! This can't be Canterlot Castle! it's not damaged!"

Rarity looks around "And we're not in the same room either..

What do you think Twilight?"

They all look over to Twilight, wearing a stunned expression.

"S-s-s-s-s-s-he's...gone...

Princess Celestia's older sister died under my watch..."

Spike runs up comforting her "T-twilight.. you couldn't do anything."

she yells back

"I KNOW! THAT'S EXACTLY IT! I COULDN'T DO ANYTHING!

DON'T YOU SEE? WITHOUT THE ELEMENTS OF HARMONY,

I'M USELESS!"

Spine yells

"TWILIGHT SPARKLE! How many more times do I have to calm you down before you realize this is foolish?

what good does it do to mope about it it? better to say you tried and failed at something,

then to say you gave up at other's expense!"

Twilight responds again

"I'm not saying i'm giving up...

But how can I talk to Princess Celestia after THIS?"

Spike comforts her once again

"Twilight it wasn't your fault...

and we don't know she's gone, there's still hope she made it out of there."

Rarity scoffs

"I cannot believe I once had a crush on that 'Prince Blueblood'

to think he attacked his mother like that..."

Applejack laughs "Technically she attacked him,

besides, didn't you get 'Nightmarified before too?"

Rarity laughs

"That isn't a word."

Applejack replies "I know it's not, but what are you?"

Rarity responds again "That insult makes no sense!"

Twilight yells "GUYS! FOCUS!

Spine is right, we've gotta figure where we are, so that-"

"HALT!" a group of Earth Pony guards yell from behind them.

"Who are you-

*GASP* You have a horn and...wings..."

*Bows*

"Your Majesty."

Twilight pushes him away.

"W-who are you? where are we? a few minutes ago we were-"

Twilight then looks to see a large portrait of 'Alicorn Trixie Lulamoon'

"THIS IS THE ALTERNATE EQUESTRIA! But how did we get here?"

The guard bows again.

"Equestria? we have not gone by that name since King Sombra was dethroned,

we are Gallantia, and how, may I ask, have you retained your magic?"

Twilight eyes wander from one side to another.

"Retained magic?...I-

What happened to your magic?"

the guard raises up.

"My apologies your majesty, I will take you to Princess Celestia, she can clue you in and what has happened since you returned home to your own dimension."

END OF CHAPTER