It's been years since the Gray Man's first mission, but the trouble's just getting started in the latest entry in the #1 New York Times bestselling series. Before he was the Gray Man, Court Gentry was Sierra Six, the junior member of a CIA action team.   In their first mission they took out a terrorist leader, at a terrible price. Years have passed. The Gray Man is on a simple mission when he sees a ghost: the long-dead terrorist, but he's remarkably energetic for a dead man.    A decade of time hasn't changed the Gray Man. He isn't one to leave a job unfinished or a blood debt unpaid. "Sharp, cinematic, and packed with action—the Gray Man novels blow all other thrillers away!" — Brad Thor, #1 New York Times bestselling author of Black Ice "So many bad guys, so little time....Over-the-top thrills. Greaney never disappoints." — Kirkus Reviews "Excellent....Greaney seamlessly adjusts focus between the timelines, jumping from one exhilarating roller-coaster ride to the other. Spy and military thriller fans will be well pleased." — Publishers Weekly (starred review) “Greaney hit absolute literary gold with his Gray Man series…and Sierra Six is no exception!” — Mystery & Suspense magazine In his research for the Gray Man novels, Mark Greaney has traveled to more than thirty-five countries and trained alongside military and law enforcement in the use of firearms, battlefield medicine, and close-range combative tactics. He is also the author of the New York Times bestsellers Tom Clancy Support and Defend , Tom Clancy Full Force and Effect , Tom Clancy Commander in Chief , and Tom Clancy True Faith and Allegiance . With Tom Clancy, he coauthored Locked On , Threat Vector , and Command Authority . One   Twelve Years Ago   Zack Hightower and the five other men of Golf Sierra watched the scene before them as if they were merely spectators, when in fact they were the stars of the show, waiting in the wings for the play to begin.   Fifty yards away from them, the ramp lowered slowly on the Lockheed C-130 Hercules. A scarlet glow shot like a soft ray from inside the cabin, illuminating the tarmac, and the plane's four massive turboprops spun at idle, growling in the cool night.   Ground crew worked feverishly around the aircraft, moving this way and that as they readied it for its upcoming flight.   The light from the cabin did not quite reach Hightower and his men on the tarmac; they remained in the dark, gazing on, interested but unconcerned.   The six men were armed and armored, festooned with heavy equipment and bulky parachutes, but they endured patiently, embracing the suck of the weight on their bodies. The sixty pounds of gear strapped to each man made unnecessary movement ill-advised, so all of them knew better than to waste energy now, before their arduous evening had even begun in earnest.   The ground crew in front of them did not engage with or even look at the operators in the dark. That was considered bad form, so the six men were left alone with their thoughts, gazing at the glowing rear of the hulking aircraft in front of them and waiting for their cue.   All six operators wore quad-tube night vision goggles stowed in the up position on their helmets. They were also equipped with rifles, pistols, and extra ammunition, as well as fragmentation, flash bang, and thermite grenades.   They'd be dealing with extreme cold soon enough, so they wore efficient merino-wool base layers under nondescript black Gore-Tex flight suits, which were themselves under plated ceramic body armor that was housed inside load-bearing vests.   Additionally, each man wore two parachutes: a main chute on his back and a reserve in front, low, cinched around his midsection. Oxygen masks were snapped tight to their faces, with two small tanks strapped just as tightly to their bodies.   The men were already consuming bottled O2 even though they were still on the ground. Tonight's mission would begin with a HAAM, a high-altitude airdrop mission-a leap from the Hercules at twenty-eight thousand feet-and breathing from the tanks now would eliminate the risk of nitrogen buildup from the rapid change in air pressure as the men descended.   These six were ordinarily a talkative bunch, but as team leader of the tiny unit, Zack demanded a strict decorum before an operation. All extraneous conversation had ceased as soon as they'd arrived on the tarmac; no one shouted through their rubber mask about what was to come.   They all just waited, heavily laden statues in the night.   Eventually the aircraft's loadmaster came down the ramp and then made his way over to the group. He looked around for a moment, obviously for some indication of who was in charge.   Zack Hightower, virtually identical in dress and load-out to the others, took a single step forward.   The loadmaster shouted, "Sir, you can board whenever you're ready."   Zack answered back through his mask in an easygoing tone. "I'm not 'sir,' chief. Just call m