The Passage (Passage Trilogy)

First, the unthinkable: a security breach at a secret U.S. government facility unleashes the product of a chilling military experiment. Then, the unspeakable: a night of chaos gives way to sunrise on a nation, and ultimately a world, turned to hell. All that remains is the long fight ahead for the stunned survivors faced with a future ruled by fear--of darkness, of death, of a fate far worse.

As civilization crumbles, two people flee in search of sanctuary. FBI agent Brad Wolgast is a good man haunted by what he's done in the line of duty. Six-year-old oprhan Amy Harper Bellafonte is a refugee from the doomed scientific project, and Brad is determined to protect her. But, for young Amy, escaping is only the beginning of a much longer odyssey--spanning miles and decades--toward the time and place where she must finish what should never have begun in the first place.