In an oil refinery deep inside the Panamanian jungle, the Talbot clan awaits a breakthrough as their scientists work nonstop to produce usable fuel. But on the verge of success, an oversight brings down the wrath of both a giant horde and the persistent Brazilian military. In a shocking development, Mike discovers a possible zombie liaison within their ranks, one that could save the day—or destroy them all—and it’s unclear which way she leans. Hostages, treachery, sacrifice and fierce battle mark this chapter in the Zombie Fallout saga...just as hope is finally on the horizon. Meanwhile, in an alternate universe, Azile and Tommy, Elam, Wilkes and Mac come face to face with an unhinged version of Michael they can’t reason with. Their only leverage is a mysterious letter from Trip, written forty years after his death. Will it be enough to persuade this vengeful, soulless monster to risk changing destiny? Or will he forsake what’s left of his humanity and kill them all?