Citadel by Kate Mosse
Five stars. It took me a bit of getting into this book, simply because it's an epic sweeping tale and I'm generally into an easy read. It was totally worth sticking in though. Before long I was gripped by the story of Sandrine, a young, somewhat naive woman in Nazi occupied France in 1942.
Sandrine is a brave heroine who gets drawn into a women's resistance group, willingly risking her life many times. There are lots of well-rounded characters in the story, a cleverly woven plot with oodles of mystery, suspense and romance. The supernatural element is an added bonus for the likes of me!
I haven't read the first two books as I didn't even realise it was the third in a trilogy, but it stands alone perfectly well. Recommended.