Supernanny Jo Frost comes to the rescue of a family caught up in a pattern of hitting, aggression and unhappiness. Jo takes Jenniffer, the mom, on an emotional journey to break the cycle of violence that was inflicted on Jenniffer as a child.

The Weinsteins need help. David, the dad, is a trucker, sometimes away from home as many as 10 days in a row, and stay-at-home mom Chia can't control the children -- McKenna (7), Christina (6), Julia (5) and Robert (2). When she tries to correct them, her temperamental brood responds by hitting and kicking her, cursing and other aggressive behavior. When he's home, David has zero tolerance for this, but his disciplinary style is more bullying than beneficial. He screams at them until they're in tears, but feels he's being put in the role of the "bad guy" because Chia has given up. The biggest issue is the nightly bedtime battle of the wills -- a two-and-a-half-hour nightmare of screaming, fighting and tears before anyone gives in to exhaustion.

Stacie and Joe Fager are the proud parents of a blended family in Iowa, but with six children, they both feel overwhelmed and exhausted. There's Sarah (8) and Andrew (7), brother and sister from Joe's first marriage; Chelsea (6), Stacie's daughter from her first marriage; and Benjamin & Zachary (4-year old twins), plus Jacob (2), who are Stacie and Joe's children together. Joe is a truck driver and full-time student, and he's gone most of the week. Stacie, a stay-at-home mom, has a hard time controlling the children, so she hardly ever leaves home with the kids in tow, and family vacations are a rarity. The older kids, Sarah and Andrew, haven't seen or spoken to their birth mother in a year, and with Joe's busy schedule, they feel as if they don't have anyone to talk to about those feelings. The family desperately needs a break and something to lift their spirits.

With five rambunctious boys in a small house, Ken and Vania have reached the end of their rope -- and possibly the end of their marriage. Vania has filed divorce papers and Jo Frost is the family's last hope for reconciliation -- if this doesn't work, Vania will move forward with the divorce. Ken is a strict disciplinarian, while Vania prefers a more laid-back method of child rearing. Rather than compromising, they've gotten to the point where they simply avoid dealing with the kids at the same time -- if one parent is there, the other is out -- and the kids have learned to use them against each other as they act up, fighting with each other and for their parents' attention. Matters are further complicated by Ken's relationship with the older boys; the little ones, Brendon (4) and Christian (3), are his and Vania's together, while Myca (5), Dawson (8) and Alex (9) are from Vania's previous relationships. Ken's biggest issue is with Alex, the oldest son, with whom he often clashes. The difference in parenting styles and the problems between Alex and Ken have brought this marriage to the breaking point -- can Supernanny get this couple back on track?

Supernanny Jo Frost travels to Hawaii to help Will and Michelle Smith -- they are highly intelligent marine biologists, but when it comes to bringing up their two boys, they're clueless. Three-year-old Nate is still in diapers, and 18-month-old Ari screams at the top of his lungs to get his bottle. Bedtime is a nightmare, as Dad hypes the boys up with a frog-hunting outing right before they're supposed to be going to bed, leaving both parents exhausted and up for hours with the two energetic boys. Will and Michelle foster a house full of high energy and crazy fun, but all their singing and dancing (including the "pee-pee dance") can't tame the kids -- they freely admit the children are totally in charge. The parents have read the books, talked to experts and still can't figure out a way to control their toddlers. Without mastering even the basics of discipline, they worry that, if they can't cope with their children now, they'll never cope with their boisterous boys in the future.

Little Sean, at just four years old, is the dictator of the Haines household, and every family member bows to his whims. He has more power than he knows what do with, and crying, whining, hitting, spitting, punching, kicking and biting seem to be his preferred methods of communication. Dad Shane is a tough police officer on the job, but he has no authority at home, and Mom Suzanne, an ER nurse, claims that giving in is easier than fighting. Big brother Seth (10) has grown resentful because Sean gets the majority of his parents' attention, so Seth antagonizes Sean to get some attention of his own. Mom and Dad's passivity when it comes to discipline has enabled the boys to spiral out of control, often out of sheer boredom and restlessness.

The four Nitti boys are at war with each other and their Mom. Darren (10), Matthew (8), Devin (6) and Jared (5) are so violent that they leave serious welts and scars -- the oldest son has hit, kicked, punched, spit and head-butted his mother, Lisa. Darren admits that he likes hitting because it "takes out his anger." Lisa and her boyfriend, John, have been together for two years, but Lisa doesn't know how to manage her children without resorting to anger or threats to call John, who has a lion's roar that intimidates the boys. The violence between the children heats up in the car, and Lisa and John often can't get more than two blocks from home without having to pull over to manage the chaos. Dinnertime can go into an hour of overtime, as Matthew refuses to eat, and when the younger kids refuse to go to bed, there's no rest for these weary parents.

John and Denise Bruno have their hands full with their four girls. Dad's got issues with the two teenagers, Mariah (15) and Taylor (13), while Mom's fed up with the two youngest, Bella (6) and Sam (4). Mariah was born with fairly severe cerebral palsy and gets daily physical therapy from Mom, but she has no physical contact with Dad, as he no longer helps her out with her therapy. Mariah craves her dad's affection. John, a very traditional dad, doesn't approve of teen Taylor's punk-goth style and strong-will; they are constantly butting heads. The most difficult part of the day for Denise is when she's trying to do therapy with Mariah and the little ones interrupt and distract them. The girls' tantrums and demands have driven Denise to the end of her rope. Jo's faced with the challenge of saving Dad's relationships with the two oldest girls, especially Taylor, before they're too far gone, and getting Denise to demand respect from the little ones and keep them from interfering with her therapy time with Mariah.

Brian McAfee is a newly-divorced father of four children living a lonely, isolated life in Alaska. Brokenhearted and bewildered, Brian has shut himself off from the world and even his own children in many ways. He doesn't know any of his neighbors or his kids' teachers. He's uncomfortable doing girly things with his daughters, which has left a big gap in their relationship with him, especially for the oldest, Ellie (9). Brian's also baffled by his son's troubles with schoolwork, their house is a disaster, and all four kids have serious behavior problems because there's no discipline at home.

Karolee and Jay Goins have a beautiful young family with a not-so-pretty problem. Mom, who is pregnant with her fourth child, is completely exhausted by her brood's out-of-control behavior: The oldest son, Khalin, 7, has attention deficit/hyperactivity disorder (ADHD), the middle child, Kolben, 5, is overly aggressive, and little Kadance, 2, is learning all of her big brothers' worst tricks. The kids' aggression and utter lack of respect, coupled with Dad acting like another child in this family, has Karolee frustrated and fed up.

Jency Williams is a single mother who works two jobs and relies heavily on her elderly grandparents to help her out with her three children, Bradley, 12, Kelsee, 10 and Hagan, 5. Jency's grandparents, who include Hal, a former catcher for the Cardinals, not only drop the children off and pick them up from school and care for them after school, they're also counted on to discipline the kids. The youngest, Hagan, treats Jency like a punching bag, hitting, punching, kicking and throwing things at Mom. The siblings continually fight with each other and do not listen to Jency. She feels that nothing she does works, and sometimes can't wait to escape to her job. The grandparents worry about what Jency will do when they aren't able to help her any longer.

Anthony and Alice Walker have their hands full. They have three children -- Anthony Jr., 12, Naleila, 6 and Alyssa, 17 months -- plus Marcus, a nephew who lives with them full-time, and a thriving daycare business based in their home. Mom's outsized personality and attitude has rubbed off on the kids, and they're doing whatever they feel like. Unsure of how to regain control, she resorts to chasing after the kids through the house, trying to catch them to mete out punishment. Meanwhile, Dad is just looking for a little peace and quiet and a good night's sleep. Naleila has her own room, but has spent the last six years sleeping in her parents' bed, and, since Mom is constantly either feeding or holding Alyssa, the baby sleeps there too -- a tight fit for all. Anthony Jr. talks back to Mom, hassles his little sister and has hit the age where he feels the need to battle his father for independence.

Nina and Paul Cantoni are at odds on how to raise their children -- Nicholas, 6, Gabrielle, 3, and Giana, 10 months. Mom is overwhelmed, especially by the headstrong Gabby who is prone to biting and tends to dominate the family dynamic. Dad is wrapped around Gabby's finger, and thinks he's defusing the tantrums by giving into them, undermining Mom as she tries to hold a hard line. Big brother Nicholas could use more quality time with Dad, but strives to get attention by acting out and talking back. Bedtime is a farce -- the household falls into turmoil as Gabby stalls goodnights by requesting drink after drink, changing her mind about her beverage preference, with Dad hopping to it.

With four kids under four, this Supermom needs Supernanny. While she's a funny character for outsiders to laugh at, three-year-old daughter Hailey's antics aren't humorous for her mom, Tamara. From using the "B" word to hitting Mom and Dad, Hailey, as "Daddy's Little Princess," thinks she's the one running the show. Adding to the chaos are twins, Jianni and Julian (age 2), with an escape plan cleverly executed every time Mom turns her back. These two get out of the house every chance they get, even getting past the child-proof latch. Rounding out the fearless foursome is baby Ashton (10 months), who gets kicked in the stomach and punched by jealous older brother Jianni. Capping it off, Dad Michael is out late every night with friends, avoiding his responsibility at home.