There is an excellent (true) account in "The Last Battle" by Cornelius Ryan of an Allied undercover agent who lived in Berlin up until the very end of the war.

There is an excellent (true) account in "The Last Battle" by Cornelius Ryan of an Allied undercover agent who lived in Berlin up until the very end of the war. I don't recall which country he claimed to be from (A non-aligned one, I believe) and due to his extended presence in the face of the worsening situation post 1943 (and Berlins general apathy towards Nazism) he was considered almost "one" of them. I'd suggest all three of Cornelius Ryan's books to anyone look for a tightly knit story style of WW2 book, written mostly in the 1950's-1960's with real interviews of those involved and excellent anecdotes.