Malcolm and the crew end their summer vacation stuck on a houseboat with Stevie's straight-edged family.
Francis officially leaves the household by emancipating himself and leaving the military academy. Malcolm faces a new teacher whose grading system wreaks havoc by causing students to compete with one another.
Lois starts attending a woman's book club, leaving Hal to attend to the boys.
When Malcolm falls for a classmate named Sara, his grades suffer due to his after-school makeout sessions. Francis is kept entertained while in jail by the town's soap opera-like happenings.
Lois forces the kids to volunteer for charity at a church. Francis arrives in Alaska and finds that it doesn't live up to his expectations.
Hal's heath scare causes tension and Lois randomly grounds Reese and Malcolm, even though they hoped to go to a party. Francis gets into a dispute with Lavernia and ends up scheduled to fight her. Dewey grows attached to the class hamster he's allowed to keep for a week.
When the kids destroy the tree ornaments, Lois threatens to cancel Christmas which causes a remarkable improvement in their behavior.
Hal spends an evening playing poker with Abe's friends, ends up losing his shirt and feels like a fool. Lois makes Reese become her dance partner and Reese learns that old people have money to throw around.
Reese starts working at a fast-food restaurant to earn money for car insurance.
Lois gets a makeover at work and suddenly finds men paying more attention to her.
The family attends Hal's company picnic, special guest stars. (Part 1)
The family attends Hal's company picnic, special guest stars. (Part 2)
Reese loses patience with his driving instructor and takes an aggressive approach to the wheel.
Malcolm and Reese notice a significant development in Cynthia's figure since before her trip to Europe.
The boys get in trouble for forgetting Hal's birthday.
Hal takes over coaching Dewey's soccer team; a neighbor bequeaths a laptop to Malcolm and Reese.
Malcolm and Reese are terrorized by a huge dog adopted by Dewey.
Reese tells girls that Stevie is dying so as to help hook him up. Hal competes with his poker buddies. Malcolm discovers a gun in the purse of one of the visiting girls.
The boys meet with a psychiatrist to reminisce about past family experiences.
Lois serves as a juror, bringing home a case which intrigues the rest of the family.
The kids return to regular school and join various cliques of jocks, goths, and skaters.
Craig gets a trained monkey to help with household chores when he's confined to bed rest. Reese assumes the role of neighborhood protector after clubbing a burglar in the house, while the rest of the family is affected by the break-in.