Some lose threads from book #3, The King of Plagues, get pulled on and things start to unravel for Joe Ledger and the DMS. It was uncovered back then that the Seven Kings had a list of all DMS members and their families, which was one of the main reasons that taking them out became so urgent. Once the Kings were all neutralized it seemed like the risk to the DMS families was eliminated but this turns out not to be true.  With Joe and Rudy in attendance to watch the Orioles play the Phillies on opening day a terrorist attack targets not just the innocent baseball fans in attendance but the DMS agents in particular. The remnants of the Seven Kings are back and this time they are making it personal.

The Seven Kings were the largest and most well funded adversary the DMS has ever gone up against and it turns out that taking out their leadership was not enough to dismantle the entire operation. But how could the Seven Kings be back without the DMS knowing it? After all, MindReader is able to infiltrate every computer system in the world so any activity on such a large scale as the Seven Kings would instantly be discovered. That would be true unless the Seven Kings now possessed a computer system far more powerful than MindReader but if that were true then the DMS would go from hunter to hunted. Yes indeed they would.

Computer technology is front and center in this one as Jonathan Maberry creates a world where all of the automation systems that are becoming commonplace have been compromised. This includes software in self driving cars, drones, and most of our high tech military assets. With the DMS blind to what is going on, the Seven Kings have been busy testing their ability to take control of anything with automated control software embedded within it. Now the time for testing is done and it is time to move forward with their plan to eliminate the DMS by attacking their families and cripple the United States in the process.

With drones and self driving cars in the news every day this one certainly makes you feel unsafe about the technology all around you. Going from the fantastical concepts of the prior books, such as zombies, vampires, and aliens, to every day real things actually made the threat much scarier. This one was action packed from start to finish and is one of the best books in the series. Ray Porter does another great job on the audiobook narration and the series keeps on going strong. Nobody is safe in this one and the dark sides of some of the "good guys" start to be revealed so it will be interesting to see where it all goes after this.