The #1 New York Times bestselling author of the Gabriel Allon series presents the second thriller featuring former CIA Agent Michael Osbourne, following The Mark of the Assassin . When the Good Friday peace accords are shattered with three savage acts of terrorism, Northern Ireland is blown back into the depths of conflict. And after his father-in-law is nominated to become the new American ambassador to London, retired CIA agent Michael Osbourne is drawn back into the game. He soon discovers that his father-in-law is marked for execution. And that he himself is once again in the crosshairs of a killer known only as October, one of the most merciless assassins the world has ever known...