General Bob Underwood is en route to Syria when a rocket-propelled grenade strikes the side of his Humvee and the heavily armored convoy comes under attack. His bodyguard is brutally murdered, and Underwood himself is kidnapped. Hours later, the president and top officials watch in horror from the Oval Office as the general is viciously beheaded by an ISIS leader-broadcast live on the Al Jazeera television network. The world is stunned by the bloody scene, but even more so that this supposedly loose-knit terrorist organization was able to orchestrate a lethal attack on the world's most powerful military. American forces goes into high gear on land and sea to retaliate. But when the ISIS leader's son is killed in an American bombing raid, his rage knows no bounds, and he determines to wreak vengeance on the American homeland itself. Now it's up to Op-Center to assemble its strike force, domestic and abroad, to stay one step ahead of a ruthless enemy-while the fate of the world hangs in the balance...