A Fatal Waltz by Tasha Alexander

As a favor to her good friend Ivy, Lady Emily Ashton has agreed to be a guest at Lord Fortescue's estate. Emily and Lord Fortescue detest each other, which makes the weekend a bit of a trial. When a fellow guest is murdered and Ivy's husband, Robert, is arrested for the crime, things go from bad to worse. Robert then asks for Emily's help in clearing his name. Emily's investigation takes her from England to Vienna, where she's immersed in the Viennese culture of the time (coffeehouses, meeting Gustav Klimt) and the world of anarchists, blackmail, and secrets. In addition, her relationship with fiancee Colin Hargreaves is threatened when she learns about his past affair with Countess Von Lange. In the end will all be well with Lady Emily and those she holds dear? A Fatal Waltz is another solid addition to this mystery series. Even though they're set in the present, the novels about Kick Keswick by Marne Davis Kellogg would be good read-alikes.