Aggressor — Andy McNab

Former covert operator Nick Stone seems to be living his dream in book eight of the best-selling series - not a care in the world as he steers his camper van around the surfing and parachuting paradise of Australia. But when he sees a news report of the massacre of women and children in a terrorist outrage on the other side of the world, long-suppressed memories are triggered, and Nick knows he must risk everything to repay a longstanding debt of friendship.
As events unfold in the teeming streets of modern Istanbul and the bleak, medieval villages of Georgia, Nick finds himself catapulted once more into the murky, clandestine world he thought he'd left behind â€" a world in the grip of nameless enemies who linger in the shadows, and stalk the corridors of power…