Mary Skelter: Nightmares[a] is a dungeon crawler role-playing video game for the PlayStation Vita developed and published by Compile Heart and Idea Factory.

[5][6][7][8][9][10][11] The game is a first-person dungeon crawler role playing game where the player guides a party of Blood Maidens through living dungeons in order to reach each one's boss, the titular "Nightmares."

The story starts with the main characters Jack and Alice escaping from a jail cell with the help of a group of supernaturally powerful girls called Blood Maidens.

It turns out the entire city has been absorbed by a malignant being known as the Jail, and it has been releasing hostile monsters called Marchens.

Realizing he has the power to assist the Blood Maidens, Jack joins their forces in order to escape the Jail.