Supernanny heads to Hertfordshire, where single mum Tara Howat is being driven to despair by her aggressive four-year-old son, who swears like a trooper and humiliates her in public. Rhys and his seven-year-old stroppy sister Shannon are locked in combat with mum. Meanwhile, eight-year-old good girl Casey gets overlooked in the chaos. From the minute the family wake up right until bedtime, the family are battling to be the boss. Rhys won't walk to school properly and runs off in public. Shannon swears, throws tantrums and hits her mother. Mother Tara's behaviour is not much better - she spends the entire day shouting at her unruly bunch - although only good girl Casey listens to her. Jo's aim is to put a stop to the aggressive, dangerous and downright disrespectful behaviour of the Howat family. And that means Tara needs to put a lid on her temper.