The arrival of new girl Chrissy triggers some alarming behaviour in apparently well-balanced schoolboy Sam.

With the death at the hospital causing suspicion, Sam must tread carefully. Jenny summons the courage to face a threat from the past.

When Sam exposes Jenny's dark secret her world begins to unravel. Sam comes face to face with his father and Jenny finally begins to understand her son's true nature.

With Sam's father released from prison, Jenny makes a desperate effort to get to the bottom of Sam's increasingly dangerous behaviour. But is she too late?