Josh Duffy is a close-protection agent—a professional bodyguard—and he's one of the world's elite operatives. That is, he was, until his final mission in Lebanon. Against all odds, Josh got his principal out alive, but the cost was high. Josh lost his lower left leg. There's not much call for an elite bodyguard with such an injury. So Josh has to support his family working as a mall cop in Virginia. For a man like Josh, this is purgatory on Earth. But even in the suburbs, miracles can occur. A lucky run-in with an old comrade promises to get Josh back in the field for one last job. The UN is sending a peace mission into the Sierra Madre mountains in Mexico, an area so dangerous it's known as the Espinazo del Diablo—the Devil's Spine. Only a fool would think they could broker peace between the homicidal drug cartels in the region, and only a madman would sign on to keep those fools alive.