I've read a lot of suspense novels over the years. They tend to fall into three categories for me. On the one hand, you have those books you can't put down, well-written, entertaining, and intelligent. Second, you have those that are for one reason or another forgettable: ham-handed politics, poor plotting, lousy writing, etc. Then there are the ones in the middle: not particularly bad, but on the other hand nothing really to recommend them either. The Fourth Perimeter definitely fits into that category.
Kurt Ford is a former Secret Service agent. He left the agency, and founded a hi-tech security firm, and has made a few billion dollars running it. Now his son, following in his footsteps, has become a Secret Service agent too, and as the book opens the author shows you how a woman and her accomplices fake the suicide of Kurt's son, murdering him. You're unsure why.
Kurt, of course, is certain that his son didn't commit suicide, the way many parents are: he had no reason, he was cheerful, etc. He goes on a quest, first to figure out why someone would want his son dead, and then for vengeance once he begins to figure things out. It's a bit more complicated than this, but once you get started with the book it will all be fairly obvious.
I didn't hate this book. I also didn't like it much. There's a dead spot in the middle where Kurt "works" in his office all day, and yells at his fiance if she interrupts him. Neither the plot or the dialog is particularly interesting or intelligent. It's an alright book, but there have been many better.