When two sisters in their twenties go missing while investigating a series of brutal murders committed over two decades before, Kendra Michaels joins the search for the missing women. The sisters' mother was one of the victims, and police seem to have had little interest in actively pursuing the cold case. Armed with the box of photos, videos, police reports and notes gathered by the sisters over the years, Kendra's investigation takes her to nearby Catalina Island, a peaceful hamlet that may be hiding a grim secret. Little does Kendra realize that her search is about to unleash a long-dormant killer on modern-day San Diego. With help from government agent-for-hire Adam Lynch, private eye Jessie Mercado and her sightless childhood friend Olivia Moore, Kendra must unravel the deadly scheme not only to save the lives of the two sisters, but also untold others.