When Lois finds her red anniversary dress burnt and in the toilet, she immediately suspects Reese, Dewey and Malcolm of foul play, and chases them all over the house to try and make them fess up, while Hal waits all night at the restaurant alone.

Malcolm finds himself being antagonized by a new bully, Kevin. This kid was always mocking him, teasing him, at lunch he cut right in front of him. On pizza day! But after Kevin taunted him about it one time too many, Malcolm loses it and attacks the kid, but deeply regrets it after learning his bully was 7-years-old; Hal cuts down the huge tree in the front yard, and he and the boys have just a little too much fun with the wood chipper.

Because of Dewey always leaving food in the crawlspace under the house, the whole family is forced to live in a trailer owned by Lois' coworker, Craig, while their house is being fumigated. However, Malcolm ends up spending more time at the home of an upper-middle-class family who has hired him as their babysitter, but he learns that they were secretly videotaping him. He later blackmails the family to leave him alone and quits the job, also revealing a horrible secret about the family's wife. Meanwhile at the academy, Francis finds the corpse of a former janitor in the basement of the military school, who was missing for 16 years, and teams up with his friends to give the forgotten custodian a proper burial by sending him down the lake in a burned boat and performing a burial at sea, which turns into a disaster.

Malcolm stays overnight at Stevie's house. He convinces Stevie to sneak out of the house with him and they go to an arcade downtown, but Stevie's wheelchair is stolen, and they have to team up to find his wheelchair while dragging Stevie in a cart. Meanwhile, to prove that he is mature, Lois challenges Reese to give Dewey a bath and put him to sleep in exchange for being allowed to stay up late to watch a scary movie, but the task proves more difficult than he expected, just as Lois thought it would. At the academy, Francis is hazed by a group of students, but tells them their tricks are amateurish to what Lois did to him, and the students decide to worship Lois.

Francis bails from military school in a desperate attempt to visit his stupid girlfriend.

Waiting in Lucky Aide for Lois to end her shift, Reese and Malcolm cause trouble, which leaves Dewey unobserved and able to nick something expensive from the store. Lois tries to make a point about "doing the right thing" and loses her job in the process. It also leaves the family with less income, bad food and Malcolm stressed out, especially because he already is in emotional despair over Julie Houlerman. Malcolm gets caught in an awkward social situation and Lois struggles between standing up to the man and providing for her family. Meanwhile Francis gets a break from the academy as honor guard for a beauty pageant. Every cadets dream come true?

Hal takes the day off and the boys to the stock car races, while Francis gets into trouble with Commandant Spangler which leads to troubles with his fellow cadets, but that can not stop Francis from aiming for the next big possibility to screw up - this time it involves a Dog and a Snake. As Lois is searching for a check, she discovers more and more dirt on each family-member, hidden in the dustiest corners of the house, which she piles up for later use. Meanwhile the boys get bored at the tracks fast and get into problems on their own.

Malcolm sucks at street-hockey, frankly because he has no skates. So he turns to his father, who trains all his sons in the secrets of skating before he allows them to have their own pair. Neither of his bigger brother tell him about his fathers training and Malcolm gets even more anxious as Hal gets very mysterious about it all, but nothing can prepare either one of them for what is to come. Lois hurt her back terribly and has to stay in bed, which does not keep her from tyrannizing Reese and constantly trying to avoid being drugged with pain medication by her loving husband Hal. At the military academy everybody is preparing for a weekend of survival training without any comfort, except for Francis who tries to ditch his comrades.