Childminder Carolyn Norwood arrives at the home of 14 month old Vicki Warwick to discover that the baby's mother Susan has been attacked and baby Vicki has been taken.
Jane Tennison has just been discharged from hospital having terminated her pregnancy. She has now been promoted to Superintendent.
When Susan starts to recover she tells Jane that she has seen a strange man with two little girls watching her and her baby in the park. The description fits that of paedophile Chris Hughes, who has recently come out of prison.
Could he be Jane's Prime Suspect?