Barry Eisler is the author of the series of thrillers featuring John Rain, assassin, loner, secret father, half-Japanese American living in--or perhaps between--two cultures. The Rain novels are stark and fast-moving, lyrical yet bleak. Fault Line, Esiler's first stand-alone thriller, shares many of these qualities
Alex Treven is a successful young lawyer in the San Francisco Bay Area. At story's beginning he's about to help patent Obsidian, a revolutionary encryption algorithm. In the opening line we learn that Obsidian's inventor is destined for murder ("The last thing Richard Hilzoy thought before the bullet entered his brain was, Things are really looking up."). Barely four pages later, he's dead, and the story takes off. Another murder, across the country, of someone involved in the patent process, then an attack on himself in his own home, spurs Alex into contacting his estranged brother Ben for help.
Ben Treven is a member of an Army Black Ops organization so secret that it changes its name regularly, to keep even the US government guessing. He's a shooter, unquestioningly performing assassinations, and when we first meet him he's just carrying out a mission in Istanbul, killing two Iranian scientist and two members of the Iranian secret police. Oh, and a Russian who just happens to be in the wrong place at the wrong time.
The reason for the simmering antipathy between the brothers is made clear as their back story unfolds between episodes. Each is so blinded by his own resentment that he has trouble seeing clearly the present day version of the brother standing in front of him, making it hard to trust sufficiently to make the partnership work.
But it does work, and after some thrilling action--and a lot of blood--the story builds to an extremely satisfying twist right before the end. There are a couple of sly and subtle references to the Rain series, which were also satisfying in self-referential sort of way.
All in all, an excellent, action-packed read.