Summary: Sian O'Callaghan goes missing after a Friday night out in Swindon Old Town. As the family desperately waits for news, the police search for any clues to where she could be.

Summary: The hunt for Sian O'Callaghan continues as Det Supt Steve Fulcher and his team see suspects come and go with no leads to follow.

Summary: Detective Superintendent Steve Fulcher takes chief suspect Christopher Halliwell to a remote location to question him about Sian O'Callaghan's disappearance.

Summary: The families of Sian and Becky discover that, despite the confession of Christopher Halliwell, getting justice for their loved ones will not be straightforward.

Summary: Detective Superintendent Steve Fulcher is lionized in the media for leading an investigation that recovered not one, but two bodies murdered by serial killer Christopher Halliwell. But behind the scenes he is facing a disciplinary hearing.

Summary: Karen takes her fight for justice all the way to Downing Street, but it proves fruitless. Fulcher's scandalous actions cost him. Last in the series.