On the land outside the mansion, a mysterious forest is there. Serafina is not allowed to go there because black magic lurks. The mansion is on top of a hill, looking down to the forest. The forest is only accessible from a winding road leading to the mansion that carriages use. This gives an ominous feel, because the mansion sits right next to a forest filled with black magic.
From what I have read, the mansion seems to be very crowded, and almost hotel-like. Only rich people seem to come, and tons of maids, butlers, and different people who help the mansion thrive.
I noticed that the book said the mansion was one of the first to have electricity, and technology such as indoor plumbing and lights. Also, it says the owner of the mansion is good friends with Thomas Edison, which is how he gets all of this. That tells me this is a time period when Thomas Edison was alive.
The overall mood of the book, and the atmosphere is pretty gloomy. When I searched this book, it said it was a horror book, which is fitting for the mood of it. When I read about the Man in the Black Cloak who had stolen the girls' soul, it gave a scary, eerie atmosphere to the book.
The time period of the book helps the story a lot. The book talks of the Edison dynamo (basically an electricity generator) as the only thing keeping the mansion powered, with light and everything that needed power. When it is sabotaged, this basically can plunge the mansion into total darkness. This allows the Man in the Black Cloak to lurk the halls of the mansion with no fear of being seen in the lights of the mansion.