An antigenic shift causes the H7N9 bird flu virus to jump species. Its unprecedented mortality rate paralyzes the nation and paves the way for martial law to be established across the country. At a maximum security penitentiary south of Tucson, Arizona, Inmate Teddy SandersÕ world of structure and routine crumbles to dust, as the virus starts spreading within the confines of the prison. As the virus callously strikes down guards and inmates alike, Teddy finds himself fighting enemies both old and new. Circumstances force him to form precarious new alliances in order to escape what has effectively become a concrete tomb. Meanwhile, a young woman named Jane risks it all to keep her son Danny safe in a residential tower in the heart of downtown Tucson. Surrounded by armed looters and desperate survivors, Jane ventures out on her own to forage for supplies. Not only does she have to contend with those left behind, but she also faces an increasingly hostile military presence.