Twilight and her five friends are transported during a botched spell, across dimensions to... Ponyville, Equestria? But not the same one that they knew. Sitting on a bench is Harpsy and Babar. The Doctoress avoids apples from an aspiring Applebuck. And in a library across town, six stallions join their forces as they try to decipher the appearance of filly look-alikes of themselves around Ponyville!

(PLEASE READ BOTTOM OF DESCRIPTION)

When Rarity's boutique is found to be hiding some dangerous stolen chemicals, the unicorn knows she's been framed. Unfortunately for her, the police won't believe her frantic explanations.
None of her friends have any idea where she has gone, and Sweetie Belle has been taken under the care of a secret organization, so it's up to this fashionista to use her wits to get herself out of this mess... Well, her wits and a new, unexpected friend.

Also, this has romance between Rarity and a convict... so read!

(NOTE: This fic is pretty much dead, and I apologize for this. It was going to take far too long to complete. If, however, you wish to finish the fic yourself with your own creative ideas, be my guest! I would love to read what you all come up with!)

Foreword
Rarity has always been strong at heart, or so we are told to believe. This story explores Rarity's dream, against Rarity's tragic love life. It exploits who she is, The Element of Generosity, and how she copes with her past. In the end, its a story about life, and how through the twists and turns, we finally reach our finish line.

Story synopsis
Rarity has been offered a chance to work in Manehattan for Sapphire Shores possibly making her one of the most important fashionistas for that time. She embarks on a journey with Fluttershy by her side in order to chase her dream. However, like every silverlining has a black cloud, Rarity is confronted by her ex-lover who has also made it big in Manehattan. Whatever happens, how will Rarity react?

Thanks to bigbaddrag for drawing the concept art

Luna discovers something hidden from Celestia for twenty years, now, with emotions running high, she enlists the help of the Mane 6... but what seemed to be a single mystery, soon reveals a darker and much more complicated plot that will soon decide the fate of Equestria.

Check out the Empty Room TV Tropes Page (Warning: Spoilers!)

Revised chapters edits and proofing (with many thanks) by: lammy, Trevor, Nick Nack, Fifth Alicorn