Derpy Hooves is a normal Pegasus, living in a small house with her daughter, Dinky and her room mate, Carrot Top. One day, her life gets flipped upside down after she witnesses her daughter getting caught in a serious accident.

Shawn Spencer, psychic detective, is a thick-tufted boy genius who ice skates through life on polished blades of snarky eloquence. He has tested himself against some of the greatest criminal minds of his time and emerged victorious... though often through unbelievable luck and not a small amount of bumbling.

Now, he faces a challenge unlike any before. One that will test his mind, his sanity, and his adaptability as he is thrust into the midst of an unfamiliar world and the ponies who populate it.

The Mane 6 face their own challenge, as an old enemy, tempered in the crimes of a much harsher world than theirs, returns to Equestria. It is a challenge they are ill-prepared for and one that only their strange, new, alien friend can help them overcome.

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