Part one of two. Former gamekeeper David Campbell stands accused of the premeditated murder of Brian Low, a 65-year-old groundsman on the same estate where they both worked. With the site of the murder exposed to the elements for days, police are unable to forensically link anyone to the deceased, so the prosecution build a case against the accused around smaller, individual strands of circumstantial evidence, while working to convince the jury that he's guilty beyond reasonable doubt