Jo takes on the four unruly young Collins children, who run the house by mob rule. She finds herself particularly up against it with nine-year-old Ben and four-year-old Joseph, who are not only aggressive and destructive, but are determined to be the first children to prove that Supernanny can fail! After witnessing everything from regular use of the F word to spitting and smashing up the house, Jo introduces her new zero-tolerance regime, under which all bad behaviour is punished. The children are separated into different Naughty Zones when they misbehave, and have toys and any luxury items confiscated. She encounters much resistance from the kids, and tears from mum and dad, and even has to teach dad how to better handle his children using a bit of imaginative role-playing.

This episode's family consists of mum Caroline, dad Sunil and the four junior J's - Jaimin, Jasmine, Jenna and Jayan. All the children are under the age of eight, and look like butter wouldn't melt in their mouths. But under closer inspection these kids are mini-adults long before their time. Supernanny Jo Frost has a different kind of mission in this house: reminding everyone who the parents are - and who are the kids. Her techniques include setting up no-go zones and the introduction of a bedtime routine for the first time ever, with new rigid times for each child. So who struggles the most with the new regime; the parents or the kids?

Older parents Doug and Sandra struggle with their four-year-old twins, George and Nicole. This pair of tag-team terrors have been known to have four-hour tantrums. The twins are at their worst when out in public. They often resort to kicking, screaming, lying down in the street, throwing items around the supermarket and generally causing such embarrassment to their parents that they just do not know what to do. Now these beleaguered parents are pinning all their hopes on Supernanny Jo Frost. Mum in particular is hoping that Jo can help her to turn things around, as she feels that her four-year-olds only ever listen to dad. Jo's clever techniques for the 'terrible twosome' include: a shopping involvement technique, tantrum control - with a calm-down zone and reward charts.

Supernanny needs to draw on all of her 16 years experience of nannying when she meets Paul and Denise Cooke and their three daughters: four-year-old Erin, six-year-old Gabriella and nine-year-old Meghann. All the girls are very bright and creative but their arguments with their parents regularly turn into shouting matches. Meghann's relationship with her mum is very stressful and the family hardly ever go out in public together for fear of an embarrassing scene. Supernanny adapts her tried-and-tested techniques to fit the Cookes' problems, with the renowned naughty step replaced by a bigger reflection room for all the girls, and attempts to improve the mood and reward good behaviour. Does Supernanny have what it takes to quell Meghann's explosive temper or has she finally met her match? And how will Mum and Dad cope when Supernanny leaves to see if they can use her new techniques on their own?

When Jo Frost meets Debbie and her daughters she's confronted by some of the most shocking behaviour she's ever seen. Debbie is a single mum who juggles two jobs with bringing up her three daughters, Bethany (5), Ruth (3) and Hannah (2). When Supernanny arrives, she's spat at and has things thrown at her - and mum doesn't do much to stop it. After laying down some household rules Supernanny adapts her famous naughty step into three 'naughty corners'. Then she teaches Debbie a 'roaming technique' to help mum regain control of the girls in public, before addressing bedtime with a strictly no-nonsense stay-in-bed technique - which eventually works after Ruth gets out a record 47 times. It all goes well at first, but then Ruth deliberately bangs mum's head against the kitchen door...

Jo Frost really has her work cut out when she meets Stuart and Laura, a kick boxing couple, and their three kids, five-month-old Diesel, two-and-a-half-year-old Tegan-Olivia and five-year-old Matthew, whose aggressive and violent behaviour often leaves mum battered and bruised. When Supernanny arrives she sees how bad the situation is. After laying down some household rules, Supernanny introduces a special 'work out your anger' chart and a chill-out chair to tackle Matthew's tantrums. Supernanny then encourages mum to let go of the reins and allow Stuart a more active role with Matthew, before leaving them to implement the techniques by themselves. It all goes well at first, until Matthew stages an epic one child riot leaving the house looking as if it's been burgled. When Supernanny returns will she be able to get the troubled family back in harness?

Jo Frost goes head-to-head with a seven-year-old girl who holds her whole family to ransom. Can Mum overcome the fear of her own daughter? Or will her little rebel reign supreme? Wendy Agate is struggling to bring up her three girls: 10-year-old Marie, nine-year-old Amie and seven-year-old Maryann; largely because of her youngest daughter's shockingly bad behaviour. She calls her mother a 'fat bitch', attacks her sisters, runs out of the house and across the road, and keeps everyone awake at night with screaming fits. Supernanny confronts Wendy, and then spells out how things are going to change: a reflection room for when the girls misbehave, a trust technique to allow the girls to go out to play safely, and a video diary room where the girls can express their feelings without blowing their top. Things start to improve - until Maryann uses the video to tell mum what she really thinks of her...

Thirty-three-year-old Michelle Ball lives in South London with her two sons, three-year-old Ryan and one-year-old Kyle. Michelle used to be an outgoing woman brimming with confidence and ambition. A Latin dance champion, she lived life to the full. But four years later she's a full-time mum and things couldn't be more different. Even though he's three, Ryan is still in nappies, acts like a baby and is violently jealous of his little brother Kyle. Even with Gran's full-time help, Mum doesn't have a minute for his baby brother, and even less for herself. Can Supernanny Jo Frost put an end to the misery and give Michelle her life back? Jo shakes up the household by sending Gran away, enforcing a strict routine, stopping Ryan demanding to be carried all the time, getting rid of the dummies and nappies, and imposing a proper bedtime routine. Things pick up until Supernanny finds Michelle in floods of tears.

Supernanny is called to deal with a food-phobic seven-year-old. But it's only when she witnesses a mealtime first-hand that she realises the extent of the family's problems. Heather and Alex Bixley live with their sons Brandon (7) and Zak (4). Brandon developed a negative relationship with food after having gastric flu as a baby. What started as fussy eating has become an obsessive fear that dominates family life. After six years of non-stop battles with Brandon, Mum is at breaking point, but Supernanny has some harsh words for her and Dad. She's horrified by the way they aggressively try and force Brandon to have food he doesn't want, and tells them they've got no chance of turning things around until they stop fighting between themselves. Supernanny introduces a menu of innovative techniques to change the boys' relationship with food, including her renowned 'little chef' technique - but the biggest hurdle is the bickering Bixleys themselves.

Supernanny Jo Frost returns to see how the Woods family are doing with their three children, 13-year-old Caitlin, 11-year-old Billy and three-year-old Charlie. Previously, Charlie completely controlled the household with his tantrums. Supernanny turned their lives around, using her renowned naughty step to discipline Charlie, involving him in tasks like getting dressed to stop him resisting everything, establishing a strict daily routine, creating a calmer bedtime atmosphere and encouraging Mum and Dad to spend quality time with all their kids. But one year on, have Supernanny's improvements had a lasting effect?