Book 3 of 3 in the Fiona Figg Mystery series.
"1917. Vienna. File clerk turned British agent Fiona Figg is more comfortable wearing a fake mustache than a ballgown. When a royal ball ends with a royal body in the middle of the dance floor, Fiona trades her dancing slippers for practical oxfords and sets out to investigate. As she tracks her nemesis, Fredrick Fredricks, from Vienna to the Austrian countryside, a hunting accident makes her rethink her loyalties."