I'm currently reading a series from Baen Books. It has mystery, Sci-Fi elements & historical(ish) fiction.
If you give it a try, I'd recommend reading a few chapters before deciding if you like the book. If I looked at the first book in a book store or at the library, I wouldn't have gotten it.
As a bonus, the first 4 books of the series can be had for free from Baen Books' library.
Belisarius Saga
An Oblique Approach
In the Heart of Darkness
Destiny's Shield
Fortune's Stroke
The Tide of Victory
The Dance of Time
The first book, An Oblique Approach is at
http://www.webscription.net/p-300-an...-approach.aspx