Les enquêtes de Nicolas Le Floch, Le noyé du grand canal - Jean-François Parot
I always like these mysteries. They're historic and set in France, which makes them even more interesting (not that I prefer French history to any other, it's just a bit more rare). This book seemed to be even more interesting than the others. The actual case, I mean. I won't go into any details, I'll just give you a few hints - a series of bizarre murders that are somehow connected to a group of singers with a special 'secret' and - a strange-smelling ghost that robs the chamberpots of the royal servants (I'm not kidding). If you can find it, read the series, that is if you're interested in historic mysteries. I know that some of these books at least have been translated into English, though I haven't read any of them. If the translator does a good job (and I have every reason to expect so) the series should be able to find many more readers.