Paul Spector's attack on Annie Brawley doesn't go as planned. She returns home with her brother Jack forcing Spector to deal with both of them. He kills Jack and Annie survives, though she is in critical condition in hospital. Spector flees the scene but arrives home to find his wife working late at the hospital and their 15 year-old babysitter in charge of the children. When the BBC shows CCTV footage of Sarah Kay, Spector's daughter also sees herself and her father walking not far behind. Spector's wife insists that he go to the police station even if he saw nothing. He does so, but his wife has to lie to provide him with an alibi leading to a major rift in his marriage, At the station, Stella Gibson speaks to Dr. Smith's friend who had a nasty encounter at university with someone named Peter. She also gets an interesting piece of forensic evidence from the letter Spector wrote to Sarah's father. After Sarah's father issues a public request for the killer to stop, Spector telephones Stella. Meanwhile, DCI Eastwood confronts ACC Jim Burns after learning that Aaron Monroe had fled their jurisdiction.
—garykmcd