Heirs of the Body, by Carola Dunn
A new mystery in an old format, Carola Dunn's series is not one I've run into before. Her heroine is Daisy Dalrymple, a mother of nearly 40 and wife to a Scotland Yard detective. It's the late 1920s and this is a good old-fashioned country house mystery.
Daisy's cousin is a peer with no heir, and finding an heir is an urgent necessity. The candidates are scattered across the world and have little documentation to prove their claims. Daisy's job is to figure out who is the real heir--and, suddenly, who is perpetrating attacks on the candidates!
It's a fun mystery. And the cover is very cute.