"See what a rent the envious Casca made."
Nathaniel Herriard -- old, monied, and always contrary -- has been badgered by his excessively congenial brother into hosting a family Christmas party at his large country house. His guests include the presumed heir and his vapid fiance, a ditzy actress/niece and her desperate playwright, an old business partner, and a commonsensical cousin. Despite amiable Uncle Joseph's best attempts, the guests drive each other batty and Christmas with the Herriard Clan, it seems clear, will not be very jolly.
And then contrary old Nathaniel Herriard is found dead in his locked bedroom -- a clear victim of foul play! Who has murdered the old crank and how? It's up to Inspector Hemingway of Scotland Yard to solve the case.
If the title of the novel means anything to you, then you probably will figure out who killed Nathaniel (and how) well ahead of everyone else. If you aren't, Heyer will indeed identify the killer to you in the end, but you will need to consult an encyclopedia or biographical dictionary to find out how -- a rather cheap trick, I feel, and it killed some of my good feeling toward Envious Casca. A pity, as all of the snide remarks, insults, and general horribleness of the Herriards to each other had given me much pleasure!
Envious Casca by Georgette Heyer (Sourcebooks, 2010)