Sian O'Callaghan, 22, goes missing after a Friday night out in Swindon, prompting Detective Sgt. Stephen Fulcher and his team to move fast to have any chance of finding her alive.

The hunt for missing Sian O'Callaghan continues as DS Steve Fulcher and his team see suspects come and go with no leads to follow; local mum Karen Edwards notices that she lives a few doors away from the missing girl's mother.

Detective Superintendent Steve Fulcher takes chief suspect Christopher Halliwell to a remote location in the Wiltshire countryside to question him about the whereabouts of missing Swindon girl Sian O'Callaghan.

The remains of two murdered women are recovered due to the actions of DS Steve Fulcher; the families of Sian and Becky soon discover that, despite the confession of Christopher Halliwell, getting justice will not be straightforward.

Karen Edwards refuses to give up her fight to get justice for Becky; DS Steve Fulcher begins to witness the consequences of his actions after eliciting a confession from Christopher Halliwell.

When Wiltshire Police find a way to bring Christopher Halliwell to court for Becky's murder, Fulcher realizes that he will have to come face to face with the man who ruined his career.