I read MacInnes back when I was a girl but haven't tried her books in years. When they became available on OverDrive I decided to try them again. She was the first woman I know of to write "spy novels". (This was published in 1944. So though I think of them as historical, she was writing about very recent history.) This book is set in the fall of 1939 and takes the reader through the invasion and surrender of Poland. It's packed full of history, and I promise you'll feel like you're in the middle of it, not like you're reading "history" at all.
The story revolves around a young British woman, Sheila, who visits a family in Poland one summer, to give herself time to see if she loves one of the sons of the family. Sheila does love the family and small town, so she stays a little longer than she should, and when the Nazis invade she's caught in Warsaw. With Sheila the reader experiences the confusion, the fear and the hard work it took to survive the invasion. Like the MC in many of MacInnes' books, Sheila becomes involved in the struggle and finds herself working undercover for the resistance.
MacInnes was born in Scotland, a librarian who married a scholar and MI6 agent. Her travels, research, and husband's knowledge all helped her write incredibly accurate novels. According to some sources, this particular book, originally published as The Unconquerable, was so accurate some thought she used classified information she accessed through her husband. I don't know where she learned the details, but I do know that her skills as a writer put the reader in the middle of the action and never let you up.
As I was reading this I realized how MacInnes shaped my view of romance in books. Our heroine is a young woman who manages to fall in love while surviving the invasion. Though there's an element of "insta-attraction", what we see happen is that their dedication to a cause brings them together, and their respect for each other is essential to their relationship. To this day I prefer my books to show me why two people care about each other and what they have in common more than lots of talk about physical attraction, which I believe fades with time.
A new MacInnes reader should be warned that the author gets a little preachy. You'll encounter sentences like, "Labels, Steve, are just misleading... They are meant for laboratory specimens, not for human beings." I don't mind this, as it shows me how passionately she feels about her values. And these are books about values. Freedom over tyranny, action over passivity, knowledge defeating ignorance. In the cynical world we live in, it can be nice to spend some hours in a world where people aren't afraid to fight for others and defend what they value with their lives.