Neighbors have the annual "The Wilkersons are gone" block party until they come home early. Reese and Dewey set up a plan to get money by letting Reese-tortured kids get revenge. Hal and Lois enter a kielbasa-eating contest and Malcolm unknowingly assists a robbery, but a surprising twist comes in the end.

Lois blows her top over a hidden 15 percent surcharge on the bill at her family's favorite pizza place and stages a boycott...but Hal and the boys are sneaking slices on the side. Malcolm meets Angela and becomes instantly smitten with her intellectual family...but starts to feel like a heel because he's asked another girl to the school dance and is forced to break it off with her--er--them. And Francis is reluctant to let Otto hire an assistant for him...but soon comes to like the idea.

When Hal and the garbageman get into a trash-dumping war (which benefits Dewey more than anyone else), Hal enlists Reese's help. Meanwhile, Lois gets her job back at Lucky Aide (off probation), and fights against Malcolm in order to take down an offensive billboard of a smiling black janitor (whose nametag reads "Slappy") holding a mop and a 6-pack of malt liquor. Soon it's an all-out war between mom and son - until Lois encounters a fellow employee who is more racist than the billboard.

When Lois catches the boys vandalizing a trashy billboard for a strip club, Malcolm alters the vandalism into a women's rights protest, which sparks a colossal media circus. In no time, feminists, conservative religious groups and national new reporters descend on the scene. After Hal grants a TV interview, a woman from his past turns up at the faux protest; and Reese, inspired by the giant billboard stripper who comes to life in his dreams, gives an impassioned speech about the objectification of women.

After Hal forbids Dewey from inviting his peculiar classmate Chad over for a sleepover, Dewey quickly finds out that his father had good reason to warm him. Meanwhile, Malcolm and Reese find out that they are not as popular as they once thought, then plot "revenge" on their classmates.

Reese befriends a pack of troublesome stray dogs; Dewey feels conflicted when he starts seeing another mother-figure; Hal unwittingly becomes a motivational speaker.

When Hal forgets to pay the family's health insurance, the company will not reinstate it until Monday, so he panics and locks the boys in their room to keep them from getting hurt.

Lois, Hal, and Dewey go out of town for a piano competition, so they get Ida to watch over Malcolm and Reese while they're gone. Since Ida thinks Reese needs to become a man, she comes up with a competition for Malcolm and Reese, and if Reese wins, he can take Raduca as his bride. Now, when Lois and Hal return, they're surprised to find out that Reese has run away to Las Vegas to get married.

Malcolm joins a local dance class to impress a girl, but when she loses her footing, he realizes that to win the competition he'll need a partner who can step it up. Dick, a rival student in the class who takes dancing a bit too seriously, challenges Malcolm to a dance-off. Meanwhile, Hal discovers an underground bachelor pad in the backyard.