"If an injury has to be done to a man it should be so severe that his vengeance need not be feared." The ninth book in Daniel Silva's smart, fast-paced series about enigmatic assassin and art restorer Gabriel Allon begins with an epigraph courtesy of Machiavelli.

A fitting start to a twisty spy thriller chock full of clandestine meetings, tenuous alliances, and ruthless men. The beauty of Silva's series is that it is easy on acronyms and byzantine operations (so you don't have to be a spy novel aficionado to enjoy it), and each book gives you a discreet rundown on familiar characters and back-stories (so you don't have to start at the beginning).

In The Defector, the disappearance of Russian defector and dissident Grigori Bulganov draws Gabriel out of semi-retirement and into the path of Ivan Kharkov, the former KGB agent and Russian oligarch from Moscow Rules. Exotic locales, intriguing characters, and a breakneck pace make for a riveting summer read.