Reece Shearsmith, Alex Kingston and Noel Clarke star in this drama about a missing persons field unit, tasked with tracking down possible serial killers. Awkward but brilliant detective Sean Stone's (Shearsmith) partnership with Missing Persons Bureau analyst Ruth Hattersley (Kingston) gets off to a rocky start. But eventually the duo's opposing skills strike the perfect balance in their hunt for societies most dangerous compulsive killers. This release includes all four episodes.