books.google.co.uk - Cloak-and-dagger work was as much a part of the ancient world as the modern. While gadgets may change, the principles do not: espionage in antiquity was just as dangerous, its stakes just as high. Without Sinon, a double agent for the Greeks, Troy would never have fallen. Frank Russell studies spies...http://books.google.co.uk/books/about/Information_gathering_in_classical_Greec.html?id=xIh_Vsbc4IYC&utm_source=gb-gplus-shareInformation gathering in classical Greece
