Right, it's been a while. Let's get things moving again.
Luke, your Challenge is... Code Name Verity, by Elizabeth Wein.
Why I loved it:
Did I mention my thing for strong female protagonists? Code Name Verity give you not one but two - one English fighter pilot crashed in France, and one Scottish captured secret agent. They are awesomely brave, and totally sassy - even though there's a war on! It's hard to say much without giving things away, but I think it's a cross between Tomorrow When The War Began and Number The Stars.
Why Luke will like it:
Luke was right into Biggles for a while there - this is just the same! Tiger Moths and crash landings and the English Channel and things. The author is a pilot herself, so that should help give this book some cred. And while he may not have read Number the Stars, I'm sure he's enjoyed the Tomorow series.