I am looking for good spy thrillers during world war 2. Even better if it is in a anthological/chronological order in a trilogy.
I was thinking of the movie when you said "Biggles." I didn't know about the books. Kind of like what happened to Matt Helm.
Look for Philipp Kerr's books especially 'Field Grey' 'The one from the other' etc etc. Also recommended Ben Pastor's 'Tin Sky'