Actually, I just finished reading about half an hour ago and I am shook. Not because it's categorised as Victorian Gothic and that it gave me a fright, but because much like her other book - The Silent Companions (which definitely scared me a great deal) - the author kept the mystery taut until the very end. The plot, according to me, highlighted two things very prominently - the power of the human mind and how outcomes hinge on what we believe in. I felt the same way, albeit less strongly, while watching Shutter Island.
This book is more like a psychological thriller, going into the very depths of the lives of our two protagonists - the seventeen years old Ruth Butterham charged with murder and the twenty five years old Dorothea Truelove, a charitable, spinster, heiress - and into the society and societal norms of that era, most probably set after the Industrial Revolution in England. The book revolves around the life of Ruth Butterham and her plight, as a young girl of no means and prospects slaving in a seamstress's shop where she is assaulted by her mistress almost on a regular basis. Assaults which sometimes are of a sexual nature, humiliating and scarring her mind. Miss Truelove is charitable woman and following her late mother's dictums, has taken the initiative of reforming the minds of the prisoners, directing them to repentance and the betterment of their souls. She tries to understand the thoughts of the prisoners by talking to them. Although, her visits do have a secret motive.
I definitely recommend reading this book :)