During a simulated battle, Reese's team of soldiers ends up getting captured because Reese has trained himself not to think; and in court, the evidence against Hal continues to mount.

Reese joins the army after Malcolm causes his girlfriend to break up with him; and Hal is placed under house arrest when he refuses to cooperate with agents investigating his company.

Lois drives to Canada to meet with her sister, Roberta, and her family; Ida vows to spend all her money to get Victor's pension; and a temporarily blinded Hal participates in a 5K race with Dewey.

Reese inadvertently perfects Malcolm and Stevie's science experiment, but can't remember how he did it.

Malcolm tries to keep Dewey from scoring high on an IQ test so he doesn't end up with the Krelboyne's, but scheme backfires and Dewey is diagnosed as mentally disturbed.

Polly begins dating Abe and Craig; Malcolm refuses to believe in the power of Dewey's lucky shirt; the ranch hands make fun of Francis; and Lois takes the kids to a baseball convention.

Lois accompanies Malcolm to his first college visit, where she clashes with a resident advisor; Reese pretends he's a drug user to woo a pretty narcotics officer.

When Hal and Lois kick Reese out of the house, he ends up renting an apartment; and Malcolm helps a dumb jock write a personal essay so he can get into college.

Lois has a dispute with Hal and the boys' favorite restaurant; Malcolm clicks with his girlfriend's family...to the point where he forgets about his girlfriend.

Lois' sister Susan comes for a visit and begins lavishing the kids with expensive gifts, including a classic Mustang convertible; and Francis and a scout troop get lost in a remote area of the ranch.

Malcolm volunteers for the company's softball team, only to realize that Lois is the coach; Francis sets out to prove he's not lazy.

Ida announces she's getting married to man who lives in Hong Kong; Malcolm gets his tongue pierced; Dewey pretends Reese doesn't exist.

Lois and Hal clash after Hal purchases a hot tub; Malcolm gets his driver's permit, only to get mixed up in a dispute between Polly and her ex-boyfriend; and Reese steals Dewey's friend.

When Malcolm becomes editor of the high school literary magazine, the principal instructs him to censor a well-written story; Lois encourages Hal to flirt with a new supervisor so he can keep his job.

Malcolm realizes the entire neighborhood has been throwing a block party when the family leaves town for an annual vacation; Hal and Lois participate in a kielbasa-eating contest.

As Christmas approaches...a layoff at work prompts Hal to make money selling Christmas trees.

Lois gets Malcolm a job at the store, exposing Lois' well-kept secret; Hal and some other fathers start betting on babies.

Malcolm's teacher forces him to secretly record Reese as he divulges his innermost secrets; Francis strikes back after a critic writes a scathing review about the hotel.

As Thanksgiving approaches, Malcolm has a shot at getting lucky with a sexy friend from school; Reese prepares a fabulous Thanksgiving meal; and Francis and Piama want a divorce.

Stevie goes into shock when he's told Kitty divorced Abe; Reese gets caught up in the hot-and-heavy entries in a diary, unaware it belongs to Lois.

When an exhausted Lois falls asleep, Hal goes out for diapers, only to be branded a shoplifter; three beautiful girls use Malcolm, Reese, and Stevie to embarrass their prom dates.

The family travels to Las Vegas when Hal experiences a dream about hitting the jackpot; Dewey and Reese enter an enormously obese rabbit in a contest. Lois gets to meet her favorite singer.