The story of Dimitrios Makropoulos,
eponymous protagonist, or at least focal center of Eric Ambler's
Coffin for Dimitrios, outside the US The Mask of Dimitrios. It's the
first great modern espionage novel. My 60-cent Dell Publishing edition
bears an imprint date of 1964, but with an original copyright of
1939. The speaker is the narrator, Cornelius Leyden--Peter Lorre in the movie--who spends the book trying to untangle the life of the mysterious (and absent) title character. I know Ambler had precursors but I'd say his work, and particularly this his best book pretty much define the genre. But then, I didn't know until tonight that he also wrote the novel behind Topkapi, which used to be a favorite movie of mine, although I guess I haven't seen it for 40 years.