Death at the Dower House by Jenna Bennett

England, early May, 1926

After the funerals of the late Duke of Sutherland and his daughter-in-law, Charlotte, (and of course Grimsby, the blackmailing valet), the younger members of the family—Philippa Darling, her cousins Christopher and Francis, and Crispin, Viscount St George—are invited to a weekend party at the Dower House in Dorset by Dowager Lady Peckham’s children, Constance and Gilbert.
Once in Dorset, things go sideways very quickly. Lady Peckham’s ward, the lovely Dutch emigree Johanna de Vos, has been making a dead set at Crispin, and has had him all to herself for the past few days. Constance’s time has been monopolized by Francis, while Pippa wouldn’t throw Crispin a rope if he were going down for the third time. However, the house party also includes the beautiful Lady Laetitia Marsden, a former dalliance of Crispin’s, and she doesn’t take the competition for his affections—or his title and fortune—lying down.
As a result, when the lovely Johanna is found murdered, the suspects are plentiful. Did Lady Laetitia decide to remove her rival? Did Lord Geoffrey, her brother, the handsy one, lose control and strangle the woman he was trying to seduce? Or perhaps Crispin was tired of the relentless pursuit, and took matters into his own hands?

When Lady Peckham also dies, miles away in Wiltshire, the case develops yet one more wrinkle. Now Pippa, with some help from Christopher, must figure out who wanted the two women dead, hopefully before the murderer can consign her to the same fate.