Stuart and Sarah Bates had two lovely boys and wanted a girl to complete their happy family. However, instead of one daughter, they ended up with identical twin terrors Erin and Orla. The three year old girls look like as sweet as pie but leave a nasty taste in the mouth with their horrible behaviour. Kicking, scratching and bullying their way around the house and lashing out at their local nursery, they have pushed mum to her wits end. Meanwhile, sons Callum and Haydn get overlooked in the chaos. Can Supernanny get the twins to tow the line? Or will teaching Mum how to relax be an even tougher task?