The Paying Guests falls little short of that bar. It starts strong in the same way--the subtle way the reader gets to know Frances through the omniscient narration, especially--but by the second act, it falls into something more straightforward that relies just on the tension of the plot and the stated actions of the characters.
Similarly to The Little Stranger, The Paying Guests begins by revolving around the collapse of a grand house after the family has lost its money. In the former work, the slow collapse of the house cleanly reflected the collapse of the family and possibly their sanity. In the latter, it’s more of a plot point, something to keep Frances constantly busy and to bring Mr. and Mrs. Barber into the lives of Frances and her mother.
When the novel opens, it seems like Frances doesn’t do much other than repair and maintain the house, cook meals, tend fires, and sit in the sitting room with her mother. She occasionally accompanies her mother to bridge or church or a movie. Then she takes a wistful walk through London, and we see her try to shake off the spinster persona. As we start to learn more about her, we see how wrong this persona is, and it immediately becomes irrelevant. Whereas the narrator’s voice in the first act seemed to encourage it somewhat, it's dropped so entirely and so soon that it seems odd that it was ever an issue.
This is certainly not the only change in tone between the first act the rest of the novel, but it’s one I can mention because it doesn’t reveal any major plot points. Later, there are some sex scenes that make it hard to believe the word “subtle” could ever be applied to anything in the book. They’re not gratuitous, but Sarah Waters so excels at that quiet cloaking tone that the scenes feel like someone has flicked on the light just after your eyes have adjusted to the dark.
All this said, The Paying Guests is still a good book that I would recommend. The plot is engaging, and the characters are worth getting to know. But it didn’t meet my expectations.