Nikki y Harry continúan investigando la muerte de Penny Harris. Harry se sorprende al enterarse de que aparentemente en algún momento de su vida había tenido un hijo, pero su esposo niega tener conocimiento de ello. Otra muerte en la familia Harris les permite acotar los sospechosos e identificar al asesino. Leo sigue buscando pistas y la policía cree haber resuelto el caso a través de pruebas de huellas dactilares, pero Leo logra demostrar que el sospechoso ha sido incriminado. La afición de las víctimas por grabar en video sus actividades proporciona una pista vital.

Alison Garland is a 14 year old schoolgirl found dead on the school grounds just after lunch. She appears to have slit her wrists and committed suicide, but there is also evidence that she had sexual relations just earlier that day. As Leo Dalton looks into the case he learns that Alison was also a school bully and was a very unhappy young woman. Harry assists the police in the stabbing death of a car dealer. The evidence suggests that he was stabbed in his garage and his body then dumped. The case takes a radical twist when they find that the knife found by Alison's body was also used to kill the car dealer. Nikki assists the police in the death of an elderly woman who appears to have been maltreated.

A third murder is discovered on school grounds and Leo realises the killings are connected to a sinister teenage pact. Meanwhile, Nikki proves her elderly victim died of hypothermia - but there is still a guilty party to be caught.