I went into reading this book knowing only the one paragraph description that most publications used to give a general idea of what this book was about (and I'm glad that's all I knew), as well as the signing recommendations of friends whose judgement I trust. So there is probably a good half-star of predisposed love for this book which elevated it from a 4 1/2 or 4 3/4 star book to a five-star. 
 I found myself going back and reading passages again, or looking up bits of information (thank you, wikipedia and World War II websites, as well as Wein's own website) and waiting to see where the story was taking me. And just when you think you might have an idea, another layer is introduced. 
 As many reviews have already said (and far more eloquently), I can't really talk about the plot without giving too much away. The highest highs and lowest lows are hit in this story of war, survival, love, and (most importantly, most beautifully) friendship.