When Detective Rebecca Madsen is assigned to a grisly homicide case, a fingerprint leads her to a shocking suspect: Jack Sylvane, a former Alcatraz inmate who died decades ago. With her investigation impeded by government agent Emerson Hauser, Madsen teams up with Alcatraz expert and comic book enthusiast Dr. Diego Soto. They both soon discover that Sylvane is not only alive, but he's loose on the streets of San Francisco, leaving bodies in his wake, and does not appear to age. With the inclusion of Agent Hauser, they realize that Sylvane is only a small part of a much larger, more sinister present-day threat. For while he may be the first, it quickly becomes clear that Sylvane won't be the last prisoner to reappear from Alcatraz.