The Informationist: A Thriller, by Taylor Stevens

Wow, this is a terrific novel.   Our hero is the strange, lethal, troubled Vanessa who also goes by Michael, who dresses alternatively as female or male (not in a cross dressing fetish way but rather as a means to get closer to her targets).   She's a private analyst who gathers information, or in this case, investigates a complex and suspenseful matter of a missing woman in Africa with many scenes in Cameroon and Equatorial Guinea.

Maybe just by a hair, maybe because the competition has been light this year, but Ms Stevens' novel made my 2011 best books of the year list for fiction.