David and Brennan target Gough as the potential killer; Lisa tries to connect him to the kidnappings; Gill threatens to blackmail David if he continues his investigation of Gough; Lisa receives a call about her father from the hospital.
Lisa's article is leaked, criticising the Gardaí for not acting on Amy's disappearance. David and Detective Brennan chase a lead, Mark Bulger. Impatient with the police's pace, Lisa risks her life to uncover what Bulger is hiding.
When reporter Lisa Wallace writes an article on her mother's murder, the killer resurfaces hinting at a kidnapping. Lisa and Detective David Burkely investigate, connecting the killer to the disappearance of a woman called Amy Reynolds.
David tries to get a statement from Teresa and a confession from Bulger, whilst Lisa investigates if Bulger could be the killer. Susan pleas for information from the Gardaí when an anonymous caller claims to have information on Amy.
Lisa has to choose whom to save between Susan and Mandy; Chris learns new information that takes Lisa to a strange address, where she discovers incriminating information.
The investigation is halted; David confronts Gardaí's top officials to expose Gill and Gough, but he finds no support; Lisa and Brennan follow a lead on the killer, investigating an abandoned slaughterhouse.