Murder in Black Tie by Sara Rosett
Olive Belgrave is about to be homeless as her landlady is getting married and selling the boardinghouse. She packs up and heads back to Nether Woodsmoor to visit her family at Parkview Manor. Aunt Caroline and cousin Gwen are hosting a house party for a small group of friends and family, including Olive's father and his wife Sonia. Olive is happy to see her cousin Peter recovering from the trauma of the war but he isn't himself yet and when a guest is murdered, Peter becomes the number one suspect. Clearly Olive need to clear Peter's name.
This is a 1920s country house party murder mystery chock full of period details, especially fashion. The history of Parkview being used as a hospital during the war and how the characters were involved with that was interesting.
I like the limited cast in house party mysteries. Our murder victim, Vincent Payne, is a businessman in the antique map business, maybe not wholly...