Lois and Hal leave the boys alone for the weekend with Francis. the boys assume that if all goes well, Francis may not have to go back to military school.

The boys stay home from school when their mother thinks it's Sunday instead of Monday. Malcolm thinks of a plan to get Francis out of trouble once again. Hal gets sucked in by a Porsche dealership.

A family weekend vacation to a casino turns into an ordeal in the desert for Hal, Reese and Malcolm, who wander onto an artillery range. Francis sneaks home, but has no one to play with.

Dewey starts carrying a purse to school. Francis's friend Richie joins him at military school. Malcolm becomes a slave to an old woman in the neighborhood.

Malcolm and the Krelboynes tutor Reese, and uncover the real reason behind his failing grades.

Trouble finds Reese at his new fast-food job; a new Krelboyne tutors Malcolm; Hal and Lois sabotage Dewey's plan to get a dog.