Ozzy appears on The Tonight Show with Jay Leno as a performer. Kelly and Sharon come with Ozzy to the show, but Jack stays at home, watching a documentary about marijuana instead.
The family's numerous dogs have been excreting far too many times in the house and ruining valuable furniture in the process. The worst dog is Lola, a bulldog which belongs to Jack. Lola has already demolished a valuable sofa. Sharon threatens Jack she'll give Lola away. Jack says Lola is demolishing the furniture because Kelly has bought a new cat into the house, and Lola is angry.
Ozzy releases his first solo album in six years. Ozzy and Sharon arrive at an in-store gig. Ozzy signs autograph sand takes photos with fans, including an entire squad of security guards.
The Osbournes have new neighbours, and they had been playing loud European dance music late at night. Sharon confronts them over the fence and tells them to go in their "perfectly big house" to play their music. The neighbours refuse to go inside, and Ozzy declares war.
Ozzy is working out with a personal trainer in preparation for an upcoming tour. Sharon talks with a friend over the phone saying that the original name for Ozzy's tour was going to be 'Black Christmas' but was inappropriate because of the 9/11 attacks and its aftermath, so they renamed it 'Merry Mayhem'. Sharon adds that Ozzy will come on stage in a sleigh that will go around the stadium.
Ozzy is touring while Sharon returns home, planning to reunite with Ozzy in Houston because she misses him so much. Kelly complains about her twisted ankle after falling into a hole exactly the same size as her foot.
Ozzy mixes alcohol with the pain medication for his foot injury and winds up stoned. He tries to take Lola for a walk, but Sharon sends Jack to retrieve him. The Osbournes suffer through a miserable Thanksgiving. Ozzy works on the video for his song "Dreamer," and adamantly refuses to wear a bat coat.
Jack invites his friend Jason Dill, a professional skateboarder, to stay at the house after he is kicked out of the home of yet another of his friends. Ozzy and Sharon are more than a little put off by the fact that Jack just lets Dill come over without telling them, let alone asking for permission.
The Osbournes are packing their stuff at the Peninsula Hotel in New York, when Sharon tells Ozzy and Jack that one of their tour truck drivers had an accident the other day.
Jack is shown walking around with a rifle and wearing army gear. Kelly complains that "15-year-old boys shouldn't be playing with rifles and knives" She brings up an old situation in which Jack had shot Kelly with a pellet gun six years earlier and she still holds a grudge.
Sharon and the dogs are in the backyard, Lola vomits on the grass and Ozzy tries to show off his knife-throwing skills by trying to throw knives into logs.
Sharon recuperates at the family's Malibu beach house while undergoing treatment for colon cancer. She vows to beat the disease, and tries to maintain as normal a life as possible. Everyone talks about their reactions to the news of her diagnosis.
Kelly travels to Europe for a series of interviews and appearances. She is upset when her bag is lost (apparently seized by security because of concerns over her gun-shaped pin), leaving her without any extra underwear.
Kelly begins dating Bert McCracken, lead singer of the band The Used.
Sharon makes amends with her father after not speaking with him for over twenty years. Kelly keeps going out and getting drunk every night, despite Sharon's pleas. Ozzy tries to warn her of the consequences of her actions, as they can't protect her if she gets arrested for underage drinking. Pop star Mandy Moore comes over to the house to hang out with Jack.
Kelly recruits her friend Sarah to play the drums in her band. However, Sarah has never had any formal lessons and can't seem to keep up with the others during rehearsals. Everyone becomes very frustrated and reaches the conclusion that Sarah must be replaced by someone with more experience.
Kelly grows frustrated with all the appearances she must make as a recording artist. She yells and screams at everyone. Sharon sympathizes with her, noting that she just wants to be a teenager and is having a hard time handling all of the demands being placed on her.
Ozzy grows increasingly tired of the dogs and their tendency to defecate in the house. Because Sharon's immune system is very weak due to the chemo, he fears that all of the germs will cause her to develop an infection.
The Osbournes pack their bags for Sin City as Ozzy prepares for a concert and Kelly celebrates her 18th birthday. Before heading to Vegas, Kelly discovers that she has been made to sign a contract with The Venetian Resort Hotel Casino as the hotel clearly states that if anyone is seen to be drinking underage, then they would all be thrown out of the hotel.
Sharon and Ozzy decide to renew their wedding vows at a hotel on New Year's Eve. Kelly is to serve as flower girl, with Jack and Robert as ushers.