The Hit, by David Baldacci

This is a very entertaining novel.  The hero is Will Robie, who has appeared in Mr. Baldacci's work previously.  He is a US government paid assassin.   As you might expect -- because it is almost always the case in this genre -- the plot requires you to suspend critical thinking to avoid disbelief.   Because the character development is good and the plot advances well, this is not difficult to do.

The Hit