In the city of Manehattan crime happens every day, many times and for every possible reason: money, desperation or even boredom to only name a few. Theft, robbery, mugging, fraud, racism and different acts of violence and intolerance are the bread and butter for the Manehattan City Guard. But there are deeds so nefarious that not even the brave mares and stallions of the guard can deal with them.

Connemara Special Investigators Manehattan (CSI for short) is a special investigation unit established to solve grisly murders and deeds so vile that no sane pony could imagine.