One of the better known flux entities within the city walls, The Killer in the Abandoned House was the result of the local belief that an abandoned house in Raven's Croft was the home of a vicious murderer. Thus, when the upheaval happened, the house did indeed have a murderer within.
The rumours of the killer stem from it being the one-time home of Willie "Two Knife" Altieri, a powerful True Council leader from before the revolution.
The Killer (and the House) now form the central part of Castle Blackthorn after Arcus Blackthorn took a liking to the idea of having a patch of flux in his basement.