by Sarah Waters.
Dr. Faraday remembers Hundreds Hall, where his mother had once been a servant, from his childhood before the war, but the house is very different when he is called there as an adult to treat the lone remaining housemaid. The family--Mrs. Ayres, daughter Caroline, and son Roderick--live in a few rooms, having closed off much of the house, and can only afford to turn the generator on for electricity a few days a week; the doctor remarks to himself that the house looks like it's starting to melt away. As Faraday finds reasons to continue visiting the family, horrifying things start to happen in the house.
This was our book club selection for this month, and a much more successful choice than last month's attempt on The Wings of the Dove. We had a very lively discussion on what exactly was haunting the house--one of us thought the building itself was possessed; we dismissed the suggestion of an actual ghost (brought up by one of the characters in the novel itself), and though a couple of us liked the idea of poltergeist activity caused by a still-living character, we couldn't agree on who was causing it.
It's a very leisurely novel, but once things started happening it got pretty creepy. I'd read more by this author.