The Darkest Hour -- Tom Wood

Victor is a professional assassin, working in this instance for the CIA.  While in the process of carrying out an assignment, he finds that he's become the target, which wasn't in the plans at all.  He escapes, barely, and it turns out that another assassin, is a woman code-named Raven.  Victor believes that he has to kill her before she kills him.  As it turns out, things are even more complicated that Victor had thought, but to tell more about the plot would spoil things.

So I'll just say that if you like chase scenes, hand-to-hand combat, shootouts, explosions, tradecraft, and an interesting anti-hero, you'll find plenty of all of that here.  One extended chase scene (40 pages!) through a totally blacked-out New York City is the center piece of the book.  

Wood tells his story is straightforward prose that moves things along very quickly.  I hadn't read any of the previous books in the series, but that was no barrier to enjoying this one.  I read tons of spy fiction back in the early to middle '60s, and this book reminded me of some of the best of those stories.  It gets a high recommendation from me.  Check it out.