Harry Pappas, chief of the CIA s Persia House, receives an encrypted message from a scientist in Tehran. But soon the source of secrets from the Iranian bomb program dries up: the scientist panics; he s being followed, but he doesn t know who s on to him, and neither does Harry. To get his agent out, Harry turns to a secret British spy team known as The Increment, whose operatives carry the modern version of the double-O license to kill. But the real story is infinitely more complicated than Harry understands, and to get to the bottom of it he must betray his own country.