Leo is called in by his old college friend,psychiatrist Sean Delaney,now a cancer-stricken alcoholic. Sean was treating inspirational,deeply religious teenager Eve Gilston,who felt neglected by her family ,and the verdict of whose death,alone in bed,apparently of arrhythmic death syndrome Sean does not believe. Accompanied by down-to-earth sergeant Brooks Leo interviews Eve's parents,lapsed Catholics Beth and Tony,wondering if the family is prone to the rare heart condition Long QT Syndrome,though John,their blind younger son refuses to be tested. Sean tells Leo that,at their last session, Eve believed that she was possessed by evil and soon afterwards Leo and sergeant Brooks find evidence that a priest performed an exorcism on her.

When teacher Lucy Chatham is abducted Nikki and Jack help police officers Andy Steemson and Karen Wretzy investigate the circumstances of her disappearance whilst Thomas assists abrasive DS Maureen Steele when ex-addict Tina Lunt is murdered. Doctor's daughter Jessica Timpson saw a car outside her house near the spot where Lucy was taken and her parents Nick and Ellie fear it may belong to Ellie's brother Alec Porter. Tina's death points to criminal boyfriend Wesley Beale whilst Lucy's sister's boyfriend Jasper Lampton is the key suspect when Lucy, his secret lover, is found dead. Forensic evidence suggests that both women were killed by the same man. Then Beale is murdered.