With their three-year-old daughter Bella totally ruling the roost, the Vernons, in the Wirral, have turned to nanny Kathryn Mewes in desperation. Simple tasks, like getting dressed or brushing teeth, are a guaranteed trigger for a tantrum - epic screaming fits that can last for hours at a time. With the couple failing to agree how best to manage their daughter's belligerence, cracks in the family are starting to show. Kathryn shows Mike and Emma how to regain control and focuses on improving the couple's relationship with their daughter. But with Bella railing against the new regime, will three days be enough to get the Vernon family back on track?