The year is 1890, and Equestria is benefiting from an economic and scientific advancement that has given them the power of steam and turned the once poor nation into a global powerhouse. Such growth has given Equestrians plenty, but where there is life, there is crime. Some crime, however, is not meant for the authorities to handle and that where Private Eye Pinkamena Diane Pie and her trusty, reluctant, and uptight kind-of-best buddy Twilight Sparkle come in.

The pay is good (and tax free), the days are fun, and adventure is always one note away. But one particular job lands them in hot water when the target they helped arrest not only somehow survives an execution, but has also devoted his time into picking off carefully selected ponies using deadly games... and the two just might be on his hit list.

Pinkie and Twilight must now survive the games, save those on the list, and stop the maniac before he ends them and completes his plan. All while dealing with the new Ponyville Police Anti-Corruption Task Force and Pinkie's unhealthy obsession with getting a coltfriend.