The story of Martha Moxley, a 15-year-old girl murdered in Greenwich in the 1970s. Her murder went unsolved for 25 years.

A killer thought behind bars is killing again. It's up to John Lawless (Kevin Smith) and Jodie Keane (Angelina Dotchin) to stop the murders.

Enigmatically silent, and driven by love, the man known as Resnik was imprisoned for butchering another man and kidnapping the young girl at the heart of his obsession, Kelly. For the safety of his fellow inmates, Resnik was only ever allowed to wake, eat and exercise alone, after dark, he learned to like it. Now having escaped during a midnight transfer, Resnik is headed back to Moonlight Bay, and Detectives Raynor and Molloy have only 12 hours to stop him before the sun goes down, and the carnage begins, again.