Van Dine's first three mystery novels were unusual for mystery fiction because he planned them as a trilogy, but plotted and wrote them in short form, more or less at the same time. After they were accepted as a group by famed editor Maxwell Perkins, Van Dine expanded them into full-length novels. All 12 book titles are in the form "The X Murder Case," where "X" is always a six-letter word (except for "The Gracie Allen Murder Case", which was originally just "Gracie").