A Useful Woman, Darcie Wilde

2018 Regency mystery, first of a series, by Sarah Zettel writing as Darcie Wilde. After her father's business dealings came to ruin and he fled with her elder sister, Rosalind Thorne has made her way in the world as a social convenience: she knows everyone, she arranges for the right people to come to the right parties, and so on. But when a young wastrel is found dead in Almack's ballroom…