Lenox is an independently wealthy gentleman who enjoys solving crimes as a hobby, though he generally prefers to pass the cold winter days in his library with a cup of tea, a roaring fire and a good book.

He is drawn into a new case when his lifelong friend and neighbor Lady Jane Grey makes a special request for his help.

When another body turns up during the season's most fashionable ball, Lenox must untangle the web of loyalties and animosities surrounding Barnard’s mansion.

The subplots of the novel focus on Lenox's evolving personal relationship with Grey and McConnell's strained marriage to Lady Victoria "Toto" Phillips, all recurring characters in Finch's books.

Kevin Allman of The Washington Post called A Beautiful Blue Death "a fine specimen of the genre" and noted that "particularly good is [Finch's] delineation of Lenox's cozy-but-proper relationship with Lady Jane.