A 4,000-year-old mystery lurks in the hills of Georgia. While investigating a strange series of ancient symbols, an archaeologist vanishes, and a professor he entrusted with the secret is murdered. Former government agent Sean Wyatt learns of his friend's disappearance and the murder. Now he must unravel the clues to the ancient mystery that holds incredible power.

Since the dawn of civilization, a hidden hand has gripped mankind. Operating in darkness with limitless wealth and power, this ancient Shadow Caste has controlled every major event in human history - mass migrations, revolutions, plagues, even two world wars. But now these ancient “caretakers” want to change the global experiment. Civilization is too successful, they believe, and our overpopulation threatens the existence of all life on earth. 

Out of work and on the run after a shocking betrayal by his brothers-in-arms, the ex-Special Forces commando hasn’t stopped moving for months. He can’t. Some of the same soldiers who left him for dead in the Middle East still want his head. And they’re getting closer. So far, he’s been lucky. But Dak is low on money and nearly out of time. All he needs is an easy gig. A place to lie low, bank some cash, and quietly figure out his next move.

At first, Dr. Gideon Wolf thinks the guy standing in front of him is insane. Ten million bucks for what amounts to a glorified treasure hunt. Ten million dollars, this man offers him, to find a mythical amulet based on, apparently, some maps he printed off the internet and his outsized faith in make-believe. Turns out the unwelcome interlocutor isn’t just some garden-variety kook. He’s Vicente Carrillo, the world’s most feared drug lord, and Gideon learns fast that the deal is nonnegotiable.

When ex-MI5 operative Joe Mason is sent to Rome to guard an elderly professor and his daughter, he thinks he’s in for an easy ride. But on their first day in the Vatican secret archives, a masked assassin gains entry, shoots Joe’s client in cold blood and steals an ancient manuscript. Giving chase, Joe can’t imagine what could lie within those pages that would make someone willing to kill. The search for answers leads Joe and his comrades in a race against time, across continents and into treacherous mountains.