The Berlin Novels consists of Mr Norris Changes Trains and Goodbye to Berlin.
Both are written in the early 30s so while these are vastly different in some ways, as I read you feel the atmosphere of the 30s Berlin; some of the roaring 20s, the poverty and the political chaos (the Weimar, the Communists and the Nazis). It is a little strange reading how people think the Nazis will disappear knowing what happened.