Before I start this review, I will say that I picked this up at the same time as Arthur Ransome's We Didn't Mean To Go To Sea (which is excellent, by the way), and somehow thought that I had picked up the Ransome to start reading when in fact it was this one. I was mightily confused by the opening set in Nazi Germany (and the complete lack of sailboats). Ahem.
So, if one picks up this book and is actually expecting it (and not a Swallows & Amazons sequel), it's actually rather good.
Set in England and Germany during World War II, it's a story told in two parts by two different narrators, about pilots, spies, and the WAAF. I found the WAAF parts particularly fascinating, as my mother-in-law served during the war. The characters were very well-drawn, the sense of place was well-presented, and I could tell a lot of research had gone into it. The story was heartbreaking (as were many people's stories during WWII, I imagine), and very engaging.
I heard about it in the New York Times' list of the year's best children's books, and I love the review by Marjorie Ingall. As she says, if I told you more about the plot, I'd have to kill you!
Oh, and lastly, from Ingall's review, about Elizabeth Wein:
"Wein’s earlier novels are set in Arthurian Britain and sixth-century Ethiopia. She has a doctorate in folklore and a pilot’s license. She met her husband at a dinner dance for hobbyist bell ringers. Nerd." Can I meet her?!