When Is Sylvia Wallace? from the Janus Project Files — Brad Anderson

Her new world began in complete silence and absolute darkness. It wasn't supposed to happen. It wasn't even supposed to be possible. All the science and technology said so, but a freak accident changes everything and Deputy U.S. Marshal Sylvia Wallace finds herself sometime in the future when the Janus Project does not exist and most of the people around her are prison escapees. All is not forsaken, however. A note from the past gives her hope. Deputy U.S. Marshal Robert Mackie (the Guardians trilogy) and Colonel John Callan (The Janus Project) are coming to take her back to her time. All she has to do is stay alive until they find her, which becomes the most dangerous time of all.