Despite the title, this hasn't a hint of horror in it. There are some Gothic nods with graveyards and a lot of fog but Copper never intended this to be horror. This is a straight-up mystery. Lazy reviewers will probably call this a Holmes pastiche, but its not. It seems that anyone who sets a detective novel in the gaslight era is bound to be accused of imitating Doyle. Its as if any detective novel set in the 1940's must be a Marlowe pastiche. You see what I mean. Despite borrowing the period and a few characters to provide unnecessary Holmesian consistency, Clyde Beatty and Dotterell are no Holmes/Watson clones.The mystery and the story are fairly entertaining but the plot drags a little once you figure out the gist of the whole thing. There is a clumsy romance involved that I think WAS meant to distinguish Beatty from Holmes but it is unnecessary. There is an almost inexplicable suicide in the middle that must have been because Copper didn't know what to do with the character anymore, or maybe a red herring to throw the reader off. Since the body was never found I kept expecting him to reappear somewhere. Copper's writing is lively but not particularly evocative. I think he could have done more with the eerie settings even within the mystery genre.