This thrilling four-part drama is set in a missing persons unit that hunts serial killers. Reece Shearsmith (The Widower, Inside Number 9) plays DS Sean Stone and Alex Kingston (ER, Doctor Who) stars as his partner, Ruth Hattersley, while Noel Clarke (Star Trek Into Darkness, Doctor Who) takes on the role of DI Carl Prior. It starts Tuesday, February 6 at 9pm on WLIW21.