Talking to the Dead by Helen Dunmore
I bought this for 10p from the community centre book stall. Beautifully, poetically written. The setting is an old country house, during a very hot summer. You feel the oppressive heat, and almost long for the inevitable storm to clear the air.
Nina is helping her sister Isabel after a difficult birth. She becomes attracted to Isabel's husband and they begin an affair. Nina and Isabel have always been close, and you start to think, maybe too close. The presence of the baby, who Nina doesn't seem to relate to as you'd expect her to, brings back memories of the girls' brother who died from cot death. Or so the story goes. Nina begins to have different recollections of her childhood days.
Isabel's a delicate character - she has an eating disorder and is agarophobic. But we begin to learn what might have caused her problems as she struggles to regain her health after the birth.
The storm, when it comes, is shocking and upsetting. This is not a cheery read, but it's a beautifully written book and I'd recommend it to fans of Dunmore.