This crime serial is based on the true story of Scotland’s first serial killer, Peter Manuel. Set in the 1950s, the series portrays a cat-and-mouse chase between Manuel and Detective William Muncie. Muncie was able to put 16-year-old Manuel behind bars in the 1940s for attacking women and burgling homes, and when Manuel finished his sentence, he vows revenge on Muncie and torments him by writing him letters. Line of Duty’s Martin Compston plays the evil, irredeemable Manuel while Douglas Henshall plays Muncie. In this first episode of the three-part series, Manuel assaults a woman, Mary McLaughlin, on her way home from a dance.