
The story is about two young women from the UK during WWII: a special operative and a pilot. The in-novel writer is the operative, who is writing down her story post-interrogation after being captured in occupied France. I promise I didn't give anything away there, that's captured in the first page. The story jumps back to when they met and continues up to the present. There's a sense that you're not getting everything, but given the state of mind of the narrator, it's hardly surprising.
I was forewarned that the book is sad, and it is, but not in a cripplingly depressing way (I don't make it through books like that). The story is actually told with joy a lot of the time, and when things get bad it's put out there plainly, not putting the reader through an emotional wringer. Thumbs up, overall.
(My one minor gripe was that near the end, they reference a short story that was mentioned in passing earlier in the book... and me being me, I couldn't remember it. Drove me nuts trying to think of it and I eventually skimmed back through the beginning to find it, even though it mattered not at all. One sentence giving a bit more context would have meant I wasn't utterly distracted thinking I was missing something for the entire end of the book.)