Title: The day the world ended
First published: 1930
Description: Adventure story involving a British reporter, an American agent, and a French detective (Gaston Max, who shows up in at least two other Rohmer works).  A mad scientist, Anubis, has plans for world domination.  If you like other Rohmer works, you'll enjoy this one.  Gothic elements plus "modern" science blend well, and the Black Forest setting is effectively presented.  The early suspense is well-handled.
Places: the Black Forest
People: Gaston Max
Time periods: post World War I (1920's?)