Four-year-old Cameron is so aggressive and disruptive that Supernanny's renowned naughty step isn't even an option. He's so out of control that his young parents Nicky and Chris Smith-Clarke have been given three weeks notice to find a new nursery for him. Cameron's rages are so extreme that the other children fear him, the other parents avoid him, and Nicky and Chris are at a loss as to what to do. Parenthood has been very challenging for Nicky and Chris. Tragically, they lost their second child to cot death when Cameron was two and since then things have spiralled out of control. Still grieving, mum Nicky finds it difficult to enforce any sort of discipline, while her husband Chris's approach is the very opposite, and therein lies the rub. It's going to take more than a stern word from Supernanny to get this boy back on track.

Dr Stephen Brickley and Dr Ann Gormley both have PHDs in neuroscience, but when it comes to controlling their two sets of twins - all under the age of five - they've run out of ideas. After years of trying for a baby, Ann and Steve had IVF treatment and were overjoyed when they found out they were expecting twins. But just one year after the arrival of Aiden and Ella, the news that Ann was pregnant with more twins didn't go down quite as well. Steve works five days a week, leaving Ann at home, but with four children under the age of five, she feels decidedly outnumbered. Aiden and Ella, who are almost five, are at loggerheads, while toddlers Louis and Ciaron give mum the run-around and refuse to eat anything other than jars of baby food. The hurdle of taking their children beyond the toddler stage is too much for Ann and Steve. All four children still drink milk from baby bottles, and they're all still in nappies at night, even though Aiden and Ella are in school by day.

Supernanny goes to the rescue of the Wynne-Jones family in North Wales. Mum Lin is being driven round the bend by four feisty children and a football-mad husband who will do anything for a quiet life. Thirteen-year-old Simone and Andrew, 10, are constantly bickering and coming to blows. Four-year-old Ben runs riot, won't stay in bed and has a dangerous obsession with electrical appliances. And then there's Georgia, a cheeky two-year-old, who's fast turning into a little version of her brother. The house is littered with locks to keep the kids in - or locks to keep kids out - there are even locks to ensure the kids stay in bed. Lin is a nervous wreck and Dad Ronny can't stand the racket. Their ten-year marriage is feeling the strain and Supernanny is their last hope. There's a lot to sort out, even by her standards, but she's going to give it her best shot.

When Supernanny met Meghhan, they didn't hit it off. The eldest of three girls, nine-year-old Meghhan was ruling the roost with her demanding, bossy, explosive temper. Her whole family were at the mercy of her moods, parents Paul and Denise were at their wits' end and woe betide younger siblings Gabriella and Erin if they dared to cross their big sister. Meghhan felt so threatened by the change that Supernanny represented that she fought her tooth and nail. Two years on, Supernanny is back to see whether her training has kept the tantrums at bay.

When Doug and Sandra Douglas were in their mid-forties, they became first-time parents - to twins - and were overjoyed when their baby daughter and son arrived. But by the time little George and Nicole had started school, incessant tantrums, biting, swearing and kicking from both twins was driving their parents to despair. Supernanny Jo Frost took the twins in hand and turned their behaviour around. Two years on, she's back in Staines to see whether the family have stuck with her training.