Both Martin Compston and Douglas Henshall have been sensational in this dark and complex real-life thriller.

And as it draws to a fitting close, we’re really feeling Muncie’s frustration and are almost as desperate as the detective to wipe the smirk from the face of serial killer Peter Manuel and see him brought to justice.

As the hunt continues for missing Isabelle Cooke, Manuel turns his sick attentions to Peter and Doris Smart and their young son Michael and claims three more lives.

But, despite putting Manuel under surveillance, there is still nothing that Muncie can do to connect the crimes to him, until Manuel pushes his luck too far and makes a fatal mistake…