Newly divorced Ben Healy and his adopted son, Junior, leave their hometown of Cold River to begin a new life in Mortville. As they enter town, Junior makes an enemy of Trixie Young by popping her balloon with his slingshot. Although Junior likes their new home, he is annoyed with the dozens of divorced women lined up outside the door, bearing baked goods. The Healys are invited to a barbecue by neighbor Alan Burger, who informs Ben that the ratio of women to men in Mortville is twenty to one. Irritated by Alan and his bratty daughters, Dolly and Madison, Junior rigs the barbecue to explode. On his first day of school, Junior is introduced to the new principal, Igor Peabody, a former child psychologist who hates children. Remembering Junior from their unpleasant encounter in Cold River, Mr. Peabody is anxious to graduate the boy as soon as possible, and promotes him from third grade to sixth grade. Junior is an object of ridicule among his older classmates, until he overpowers Murph, a bully who has spent much of his life in the sixth grade. Meanwhile at the bank, Ben Healy unknowingly becomes the love interest of town oligarch Lawanda Dumore, who is attracted by his resemblance to her six ex-husbands. Later, as Ben meets his son outside school, he is struck by a falling television satellite dish, which Murph had intended for Junior. Ben awakens in the infirmary to the sight of school nurse Annie Young, and exaggerates his injuries as an excuse to extend his stay. In the waiting room, Junior attempts to deface Annie’s photograph, but her daughter, Trixie, uses martial arts to stop him. Sometime later, Ben takes Debbie Claukinski to dinner, leaving Junior with a babysitter named Rhoda. Convinced that Debbie is trying to usurp his father, Junior telephones her ex-husband, Voytek Claukinski, who has been living in poverty since the divorce. Junior coerces Voytek to intrude on his father’s dinner date, which results in the Claukinskis getting back together. He then places a video camera in the master bedroom, where Rhoda and her “skuzzy” boyfriend are making love, and projects the image on the front of the house. Late in the evening, Ben’s father, “Big Ben” Healy, appears at the door, accompanied by his deranged dog, Nippy. Big Ben begs for lodging because his latest business venture left him destitute, and he is assigned to Junior’s room, where he thoughtlessly imposes on the boy. In school, Junior learns about Mortville’s signature attraction, the “Love Rock,” a spherical boulder with the impression of a red heart, reputed to possess magical powers. Junior follows Trixie through the halls with a slingshot, and she retaliates with a fire hose. When Ben picks up Junior from the infirmary, he invites Annie Young to dinner, but she declines, citing an unnamed problem that limits her personal involvements. Determined to find a new wife, Ben makes a date with a woman named Emily, which ends badly after Junior attempts to electrocute her. Tensions build between Junior and Big Ben, leading to a confrontation that leaves the old man stranded in a tree. Believing his son is starved for attention, Ben offers to spend the day with Junior. They visit a carnival, where Junior is barred from the “Crazy Dance” ride due to arbitrary enforcement of a height requirement. He sabotages the ride, resulting in chain-reaction vomiting among the passengers. Afterward, Ben explains that his need for a social life is not an affront to Junior, and demands socially acceptable behavior from his son. They return home to find their house gaudily redecorated by Lawanda Dumore, who claims the service comes with each new checking account. Junior makes a subtle protest by knocking over a potted plant, prompting Lawanda to threaten the boy if he interferes with her plans. Big Ben encourages a prospective romance between his son and Lawanda, certain that she will finance his next venture. Lawanda makes dinner for the family, which Junior ruins with a swarm of cockroaches. Afterward, Lawanda informs Junior that she will transfer him to an Iraqi boarding school after she marries his father. During an open house at Mortville Elementary School, a patriotic puppet show turns obscene, and Ben holds Junior responsible, until Annie Young exposes her daughter, Trixie, as the culprit. Ben and Annie bond over their mutual struggles with their children, but she continues to refuse his advances, explaining that Trixie occupies all her time. Certain that Annie can never return his affection, Ben settles for Lawanda, who persuades him to marry her the following Saturday. Hoping to delay the ceremony, Junior contaminates Lawanda’s blood sample with rabies virus, resulting in her hospitalization. When Lawanda insists on having the wedding in her hospital room, Junior switches her chart with a neighboring patient who is having his nose extended. That evening, Ben and Junior encounter Annie and Trixie at a restaurant and join them for dinner. The children notice Mr. Peabody at a nearby table and engage him in a food fight. As the two families are escorted from the restaurant, Junior and Trixie agree that Annie and Ben belong together. Meanwhile, Lawanda awakens in the hospital and emits an anguished scream at the sight of her enormous new nose. The children make their way to the Love Rock and wish for their parents to marry. However, Ben stifles his feelings for Annie and proceeds with marrying Lawanda the next day. Lawanda arrives with her nose completely restored, achieved with $380,000 worth of emergency plastic surgery. Trixie Young halts the wedding by commandeering a bulldozer and rolling the Love Rock over the bride. Ben thanks the children for their interference and declares his love for Annie. Desperate for the Dumore fortune, Big Ben proposes to Lawanda and she accepts. With the help of Junior and an M-80, the wedding cake is propelled through the air and hits Big Ben and Lawanda.