The end of the 1800s. A girl named Wisteria is peddling wares. She lives in the attic of a church and her only joy in life is the fact that the demon Marbas comes to visit her if she knocks on the far most window three times.
Marbas and Wisteria have forged a pact to be together, but the world doesn't take too kindly to dealing with demons, and now a familiar knight from the Sword Cross order is tracking them down.
Forced to confront the likelihood that Snow may have been lost forever, Wisteria and Marbas decide to search for him anyway, while the Commander of the Cross Sword Knights clashes with Dantalion and Luther.
Snow, freed from Sytry's grip, assists his sister and Marbas in their fierce fight against Luther and Dantalion, who unleash their fury. The little girl and her devil will do everything to stop them.