There are a few things about Sarah Waters' books, the fact you can't put her books down, and read them at the speed of light and also that she REALLY knows about the era she's writing about. All that same quality is in this novel.
The story follows the intriguing stories of four main characters; Kay, Viv, Helen and Duncan. The characterisation is fantastic and you don't have to read too much before you really get a sense of the type of person each character is and become totally absorbed in following the characters.
It's a very clever novel, starting in 1947, then going back to 1944 and ending in 1941, so as the blurb suggests, you end with the beginning. Like a previous reviewer I felt the last section wasn't really needed as it didn't further what you needed to know about the characters and for me personally I'd have prefered to have gone back to 1947 by that point as it felt like some of the storylines were left with loose ends.
The setting of war-torn London is brilliantly presented and described to the reader, and the sections on Kay and her work in the ambulance service are very gritty, realistic and historically accurate; going to bomb sites to deal with the injured and dead and how that affected her personality.
It's also excellent writing setting the scene and situations faced by the ordinary women working in London in the 1940s, and the things faced every day by people trying to go about their own business.
Throughout the book there is a wonderful suspense and tension and little things revealed all along, with some wonderful twists and plot links. A really good book should always leave the reader wanting more, but after reading this book not only did I want more, but it felt more like it was unfinished and I felt several things were left unresolved, unless of course that is the author's intention.
This is still a superb read though, and highly recommended.