Dorothy, who serves as a warrior nun, has been tasked with locating and exterminating supernatural entities in a deteriorating gothic city. As a distinguished member of the esteemed Crimson Sisters, she is committed to eradicating every vampire. But fate takes a hand when she encounters Maria, a stunning but fanged creature who is wounded and in dire straits. Dorothy throws Maria a lifeline, proposing a unique chance for her to stay alive: become her trusted ally.