I'll say first and foremost that I loved this book. I found the characters intoxicating and fascinating. Their voices are incredibly present, their motives flow from scene to scene; I always understood why they did things, and how those actions grew naturally out of who they were. It was great.
The plot follows the evolution of a family of upper-class(ish) women in 19th Century New York as they encounter, and are changed by, the lives teeming in the city around them. It's difficult to go into much detail without giving away the story but, essentially, two female doctors -- cousins -- in the early years of women's medical practice in the United States, find themselves embroiled in controversies and conspiracies arising from hypocrisies that are both uniquely Victorian, and sadly applicable to the age we live in now. Along the way they meet housewives, nurses, charming police detectives, printers (also charming), ambulance drivers, ambulance chasers, politicians, orphans, criminals, clergy and inquisitors. The ensemble cast is enormous, yet Rosina sketches each character as a complete person, with his or her own motives, and conveys them so thoroughly to the reader that, when a number of important events occur "off-screen", as it were, there is little need for explanation or exposition. The clarity with which events are implied, and the ease with which they are inferred, is one of the great joys of Rosina's writing.
New York is here too, in all its decadence, hope, and savagery. And I suppose I'll say a few words about that as well, because depictions of late 19th Century New York tend to go either Age of Innocence, or Gangs of New York, but not both -- until now. The lives of the upper crust, famous and notorious, are shown in all their splendor, cheek by jowl with the lives of the middle class, the working poor, and the poor criminal classes, with an honesty that is enthusiastic, appreciative, and pleasantly unromantic. Neither are they separated by chapters or point-of-view characters, as some authors would choose to do. Instead, they're all mixed up together, as they likely were in real life, and the result is that the entire city, and all its people, are present for the reader moment to moment, scene to scene.
The Gilded Hour is a remarkably good book. Its characters have stayed with me in the weeks and months since I first encountered them, and I'm desperate to know how their stories progress. The worst thing about the book, really, is that I'll have to wait to read the second one.