Secret Service Agent Carlie Simmons began her day surrounded by trusted colleagues in an inter-agency shooting competition in Tucson. It ended with a staggering body count as the world around her unraveled from a deadly virus. With her mission to extract the President’s daughter from the University of Arizona gone awry, she must choose between her sworn duties and her moral obligations to others as the city is overtaken by roving packs of flesh-eating mutants. If she and her small group are to survive the night and find a way out of the ravaged city, she will have to summon all of her training, mental prowess, and tactical abilities.