Recently elected valedictorian of his graduating class, Malcolm struggles with his speech, but Lois refuses to hear his complaints and reveals her plans for him to become President of the United States. Meanwhile, Reese will do anything to get a permanent job as the high school janitor, even concocting the most disgusting mess of all time, which explodes all over the family. At home, Hal struggles with Malcolm's Harvard tuition and Francis lands a "real" job working 9 to 5 in a cubicle and enjoys every minute of it. Grandma Ida returns for the family festivities, and they all bid farewell to Malcolm when he leaves for college.
Malcolm is a regular high school kid trying to navigate his way through life despite the various obstacles thrown in his way a complete misunderstanding of girls, the constant burden of masterminding plans to get himself and his brothers into or out of trouble, and a miserable job at the Lucky Aide not to mention a severe case of teen angst.
Although Malcolm has a genius IQ, he can't seem to make sense of the opposite sex, much less his embarrassing family. Lois is the outspoken, opinionated mom, who still manages to rule the roost even though her boys are growing wise to her crafty ways. Hal, a dad who is just a bumbling, big kid at heart, often finds himself creating more chaos than his five boys combined.