Malcolm, whose frenetic home life is a kind of zoo, begins the fourth season by accompanying his family to the real thing. A visit to the zoo offers close encounters with creatures great and small. But Hal wishes he could have passed on an encounter with Lois's former beau, who lectures on rain-forest animals. Elsewhere, Reese butts heads with a goat; and Malcolm and Dewey take a tumble into a tiger den. Another storyline checks in on ne'er-do-well Francis, now the unlikely foreman of a dude ranch owned by a cheery German businessman.
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.