Instruments of darkness, by Imogen Robertson

This interesting mystery is set in England shortly after the American Revolution, with flashbacks to events in America during the Revolution. There are plenty of plucky, quirky characters and the story rolls along at a pretty good pace. You don't want to trust any of the characters, but you'll probably figure out who the grand master of the crimes is before the confession is made.
audio: 12 hours
print: 373