by Georgette Heyer...not a Regency, not a romance, still highly entertaining!
A gathering of irritating people try to celebrate Christmas together, culminating in murder. You wouldn't think this story would be fun, but it is. The minor characters run away with the story at times--hilariously. The guys from Scotland yard provide side-splitting dialogue.
By the time Nat is stabbed, we are ready to dispatch with several characters as outraged readers. The ending is bound to surprise unless you can't resisting reading ahead. An unexpected romance blossoms while another dies, and a couple "idiotish" characters are not what they seem.
The setting is during the radio rather than TV era. Cars or trains, not horses, convey people, so it's safe to say the setting is 20th century England. This work reminds me somewhat of Barbara Michaels (aka Elizabeth Peters) but with more humor.