After reporter Lisa Wallace publishes an article on her mother’s murder, the killer resurfaces hinting at a kidnapping. Lisa and Detective David Burkely start investigating, connecting the killer to the disappearance of a women named Amy Reynolds.

Lisa’s article is leaked, criticizing the Gardaí for not acting on Amy’s disappearance. David and Detective Brennan chase a lead, Mark Bulger, in Castlemoy. Impatient with the police’s pace, Lisa risks her life to uncover what Bulger is hiding.

Lisa has to choose who to save: Susan or Mandy? Chris learns new information that takes Lisa to a strange address, where she discovers incriminating information that someone tries to cover up. The killer calls later that evening for Lisa’s decision.

David and Brennan target Gough as the potential killer while Lisa tries to connect him to the kidnappings. Gill threatens to blackmail David if he continues his investigation of Gough. Lisa faces her worst fear with a hospital call about her father.

The investigation is halted. David confronts Gardaí’s top officials to expose Gill and Gough but finds no support. He reveals a long-hidden secret to his family. Lisa and Brennan follow a lead on the killer, investigating an abandoned slaughterhouse.