Greaney is known for keeping an eye on the current world political stage, and his stories are rooted in real world events. He's also traveled to over 35 countries to extensively to research each novel's location, as well as gotten firsthand experience in firearms training, scuba diving, stunt driving, SWAT training, Navy fighter plane flying, field medical training, and more. If you're a fan of Greaney's Gray Man series or action-packed of spy thrillers, Greaney's Armored series features a very different kind of action thriller hero: Joshua Duffy, a Close Protection Agent-a professional bodyguard-one of the world's elite operatives. That is, he was, until his last mission in Lebanon. Against all odds, Josh got his principal out alive, but the cost was high. Josh lost his lower left leg. This makes Josh Duffy a different kind of protagonist than Jack Ryan, Court Gentry, Mitch Rapp, or Pike Logan. With a substantial injury, a wife, kids, and a mortgage, Josh is one of the most realistic characters in this genre. ARMORED (the first in the series) began as a script for an audio play that Audible produced and gave away to its listeners; it was so popular Mark decided to turn it into a full-length novel. In SENTINEL, an African coup may force Josh Duffy to choose between his mission and his family. Josh Duffy and his wife Nikki are both working for the State Department's Diplomatic Security Service providing protection for diplomats in the field. They've been sent to Ghana with a team of US embassy personnel who are there to highlight American commitment to the construction of a new dam.