I think what I like best about Louis Bayard is the fact that though he writes historical thrillers, they're as fast-paced as any modern suspense novel. In The Black Tower, he turns to post-Revolution, post-Napoleonic Paris, where a young doctor teams up with the legendary detective Vidocq to discover whether or not the dauphin managed to survive - and escape - his imprisonment in Paris' fearsome prison.
I admit, sometimes when I see the words "historical" I cringe, because it can be an excuse for massively descriptive prose that neglects plot to show off the author's research into whatever period he's writing about. Bayard - who also wrote Mr. Timothy and The Pale Blue Eye - has opened my mind a bit.
You can read the review of The Black Tower here.