The duo look into the murder of an eight-year-old boy, coming up against a paedophile who cruelly deceives his victim's family. Dom's HIV test comes back negative, so he sets out to celebrate - only to endanger his own life and jeopardise Rachel's sergeant's exam in the process. Janet tells Andy she is having second thoughts about their brief liaison, but he finds her decision hard to accept. Suranne Jones and Lesley Sharp star, with Liam Boyle, Nicholas Gleaves and Joe Duttine.