Portrait of an Unknown Woman by Daniel Silva

Gabriel Allon, formerly head of the Israeli intelligence service, has moved to Venice with his family with plans to return to art restoration. Then he gets a request from an old friend to inquire into the death of a French woman who wondered if a painting she owned was possibly a forgery. Gabriel starts investigating and realizes that there is a huge art forgery ring at work--with millions of dollars of art fraud occurring. 

It's quite the page-turner. I like the character of Gabriel and am interested in seeing where this series goes now that he's "retired," not that he's had much time to do art restoration.