Nikki's suspicions about David Cannon are roused further when she discovers blood in the boot of his car an with Thomas's support she takes samples to process. Does it belong to Sally Vaughn? Meanwhile, the uncovering of the body from the 16-year-old... (more) murder shines the spotlight on three people who went to the same school. Emilia Fox stars, with Julian Rhind-Tutt and Alex Macqueen.