When Lois and Hal force a reluctant Dewey into the humiliation of door-to-door candy bar selling, Dewey adopts underhand tactics to get through the unbearable task. He tells each one of his neighbors all profits will go to good causes - and sales go through the roof.
Meanwhile, Malcolm and Stevie are wracking their brains on an impossible science experiment.
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.