This murder–mystery novel is notorious as a roman a clef, that is, many of its characters are thinly–veiled portraits of real people — more particularly, well–known science–fiction writers in the Los Angeles area in the period immediately before the Second World War. (In fact, the action takes place just one month before Pearl Harbor.) The venerable LASFS itself appears in the guise of the “Mañana Literary Society”. We are, however, at a loss to know why nobody ever returned the favour by writing stories of the adventures of Dr Derringer, the fictional–within–the–fiction character so crucial to the plot.