Clinical Psychologist, Dr Tony Hill and Detective Inspector Carol Jordan are reunited for four more dark and disturbing cases, hunting brutal killers terrorising the northern town of Bradfield.

An obsessive fascination with the fractured criminal mind, leads Dr Hill and D.I. Jordan on an intense and vivid journey into a dark world of faceless serial killers. It is a race against time as they try to anticipate the killer's very next step, and identify the next possible victim, each case putting more pressure on their close relationship.

Vulnerable and lonely children are being abducted and murdered in the first episode "Redemption", but what is their connection to a similar case some years before? A notorious killer has been released from prison and it's not long before the brutal slayings start again, bearing all the hallmarks of the infamous "Mack The Knife". Exactly how "safe and rehabilitated" is one Michael Thompson and is there really such a thing as "Bad Seed"?

Life is imitating art in the tense case "Nothing But The Night", as a schizophrenic killer leaves his taunting messages scrawled over walls, in his victim's blood, and what does Tony's "wife" have planned for Carol?

In "Synchronicity", Tony is forced to confront his own mortality whilst hunting down an anonymous sniper. But is anything real anymore? Who can he trust?

Special Features:

• Photo Gallery.