Even in the golden heart of Canterlot, ponies are not safe from crime. From petty theft to vicious murder, somepony has to keep the streets safe. Somepony has to pick up the pieces. Somepony has to find the criminals before they strike.
Luckily, they don't do a brilliant job - or I'd be out of work.
So, hello there - the name's Nocturne - investigator of obscure crime, back-alley stabbings, and part-time foal-sitter. Currently working for the least successful private detective agency in the whole of Canterlot.
Oh - and the prime suspect in a high profile murder.
That last bit might be the most important, actually...

Edit completed 29/8/15