It must be tough being a thriller writer, trying to come up with an original plot. In a crowded genre, it seems that almost every base has been covered, so one option is to take an old idea, and try to add to it, which is the path chosen by Matthew Quirk here. He takes Grisham's idea for "The Firm", replacing a law firm with a political lobbyist and adding a back story for the hero and a larger dose of action - and he pretty much pulls it off.
The writing style is pacy and Quirk is brave enough to set up the ending before he tells the story, which has just enough complexity to avoid standard action thriller status. This is where that back story for the hero works well, adding depth to Mike Ford's character as well as the plot. The minor characters are also well fleshed out, although at times, the villians are a little too stereotypical, while the basic premise for the plot will please conspiracy theorists, without strainiing too hard at credibility.
It is only as the denouement approaches that things begin to get a little stretched, but until that point, this was a good a thriller as I have read in a long time. If you read "The Firm", try this, I think you'll like it.