A Jason Bourne Book 3: The Bourne Ultimatum

Carlos the Jackal is calling Jason Bourne's cards. He has to show. Two men are summoned by telegram to a small-town funfair. There they witness a bizarre killing. Carlos the Jackal, Jason Bourne's long time antagonist, is back. Forced out of an idyllic retirement, Bourne must leave his wife and children to face his enemy - and confront the secret society of Medusa, a relic of war, now seeking ultimate power in peacetime. Bourne's plan is simple: to use himself as bait to lure the cunning Jackal into a deadly trap - a trap from which only one of them will escape..