Ciel Phantomhive's first few cases were quite eccentric. His responsibilities as the Queen's Watchdog lands him in Ireland with a village of people terrorized by a 'cursed' castle that unleashes its wrath on anyone who enters it, along with Eilish Kiernan, a knighted noble with odd servants and an even stranger home. And to top it all off, an enigmatic girl with inhuman power.

Miloh Ferreira has never seen the sun, nor the moon. She hasn't seen birds, trees, grass, people, or the gigantic walls that both trap and protect humanity. Born in the Underground with a mysterious condition, she has always had bandages tightly wrapping her eyes shut. In the year 845, there is a "special orphanage" for girls. And a certain girl is going to avenge its destruction.