When San Francisco Police Department Det. Rebecca Madsen (Sarah Jones) is assigned to a grisly homicide case, a fingerprint leads her to Jack Sylvane (Jeffrey Pierce), a former Island prisoner who died decades ago. Given her family history— both her grandfather and surrogate uncle, Ray Archer (Robert Forster), were guards at the prison —Madsen's interest is immediately piqued, and once an enigmatic, government agent Emerson Hauser (Sam Neill) tries to impede her investigation, she is doggedly committed.