The Mark Of The Assassin by Daniel Silva

Very enjoyable. Gabrielle is missing, but some familiar characters drift through. The ending is weak. Set in London, Cairo, Amsterdam, and Washington, the story line follows CIA case agent Michael Osbourne as he attempts to locate the terrorists who shot down an airliner off the coast of Long Island. Osbourne has two main antagonists: Delaroche, a KGB-trained expert assassin ordered to kill the handful of people who know the truth, including Osbourne, and the corrupt political culture of Washington, which ominously stymies him at every turn.