Before Fillydelphia there was Manehatten and before there was Gilda there was Mare-Do-Well.

Pinkie Pie had cleaned up Manehatten for the better. The cops were honest, the gangs were gone, and a friend's honor was protected. Pinkie had a wealth of experience being a masked heroine for the city that never sleeps, but while the roving criminals were all but an afterthought a single mare rose up to grip the city in fear. With a string of horrific murders our heroine will be pushed to her limits and beyond to stop this monster in pony clothing.

Mare-Do-Well won't be alone as her friends and mentors, Rainbow Dash and Twilight Sparkle, join her in a race to find out who is killing ponies and stopping them.