When news hits that Hal may have a serious illness, Lois becomes meaner than usual and punishes Reese and Malcolm for tracking mud. And again when they go to a party during night without permission, leading to Reese shouting "THIS FAMILY SUCKS! YOU ARE RUINING OUR LIVES!! I WISH YOU WERE DEAD!!!" at Lois and Hal.
Meanwhile, Francis has a showdown with combative Lavernia in Alaska, and Dewey becomes overzealous in taking care of his class's pet hamster, by putting it in its play ball and filling it with cereal, and setting it free to protect it from a mean bully.
In the cold opening, Hal arrives home and finds that the kitchen lightbulb is burnt out, when he goes to get a new lightbulb he finds that the shelf is loose, when he goes to screwdriver to fix the shelf he finds that the drawer squeaks. He goes out to the garage to get some WD-40 to fix the drawer only to find that it is empty. When he gets in the car to go buy more WD-40 the car engine dies frustrating him. Lois comes outside and asks Hal to replace the kitchen lightbulb, Hal repairing the car yells out "What does it look like I'm doing?"
Dewey is caring for Bernard whom is his teacher's pet for the weekend. He tried to convince Hal and Lois that because he was taking such good care of Bernard, then he could have the responsibility to have a pet dog. When news hits that Hal may have a serious illness, Lois becomes meaner than usual and punishes Reese and Malcolm for tracking mud.
Meanwhile in Alaska, Francis tries to talk to Lavernia and convince her not to overwork him, Artie, Pete and Eric. When this fails, Francis mocks her hair, resulting in Lavernia getting very combative and Francis having to fight her.
Later, Lance, a bully at Dewey's school confronted him on the sidewalk, saying that next week, he would be the one taking care of Bernard, and made it obvious that he was going to abuse him when he did. Wanting to save him, Dewey tries to get Lois and Hal to help save Bernard by asking the teacher to let him keep the hamster. He points out he knows what Lance is like on the inside and has killed his own pets with his abusive nature. Lois gives Dewey a resounding NO! and reminds him that she and Hal have bigger issues to deal with. He decided to set Bernard free to live on his own, instead of being abused by Lance. So, Dewey put Bernard in a hamster ball and filled it to the brim with Cheerios and set him outside. He tries to roll back to Dewey. He encourages Bernard to roll away to freedom and live on his own. Bernard rolls his way to freedom and Dewey tearfully bids him farewell.
At the Boys bedroom, Malcolm comes up with an ingenious plan to get him and Reese to Tracy's party. He goes over his plans with Reese in how he was able to dig a hole to lead to a crawlspace and help with their escape. That night, he and Malcolm pretend to be in bed and once everyone is asleep, they wake up quickly go to work. Reese puts a mirror under the door and informs Malcolm it's a classic booby trap with a broom tied to cans. Malcolm puts a zombie mask over a teddy bear and Reese draws a face on a balloon. The two boys sneak off to the party through the hole and crawlspace.
Francis turns off the lights and gets ready to head for bed. He hears punching from the refrigerator and opens it to see Lavernia punching a long pork meat as her punching bag. This makes him seriously regret challenging her.
Hal heads into the boys bedroom to apologize to Malcolm and Reese for Lois being hard on them and is just worried over his possible cancer. He gives his heartfelt "I love you" knowing he could end up suffering cancer and how they would have to struggle with paying for his treatment. Once he kisses what appears to be Reese's face the balloon pops and he screams. Dewey wakes up to see a zombie mask in front of him and screams in terror at the same time as Hal. Lois then wakes up and heads into the boys' room. She quickly discerns that Malcolm and Reese sneak off to the party against her wishes. Lois wonders aloud how they were able to get past her booby trap and sneak off without making too much noise.
Malcolm and Reese are having a good time at the party and head home. After leaving, Bernard is seen rolling his way to freedom in his ball. Once home, Malcolm and Reese are still excited over it and put the boards back on the hole. Reese mentions that they would get a few weeks grounding. He would come to regret those words when he and Malcolm open the door of the closet. The two older boys notice the angry Hal and Lois sitting on the top of the drawer waiting for them, having now found out that they sneaked out through the closet. Malcolm and Reese screams in terror knowing their grounding will get much worse from there on out.
While Lavernia is training, Francis comes and tells Lavernia that he hates her for her cruel nature, but apologizes for insulting Lavernia for her appearance instead of her personality, and tells her she doesn't have anything to prove to the other workers. Lavernia takes this as Francis hitting on her, and tells him the fight is still on.
In the kitchen, Lois shouts at the two older boys for going against her wishes to stay home. Malcolm shouts back, pointing out that they wouldn't had rebelled against her had she just let them apologize for tracking a little mud on the floor. Lois points out that he and Reese are the worst behaved, inconsiderate and ungrateful brats she had given birth to. Dewey is obviously amused over his older brothers being into trouble again and is eating Corn Pops. When Lois announces that she plans to ground both Malcolm and Reese for the rest of the school year. Reese has enough. He tells her off that he and Malcolm are fed up with her and Hal trying to ruin their chances of a normal life and wishes that their parents were dead. Although this would be a regular insult at any other time, this time both parents are shocked and unable to respond. Lois walks away and an Hal follows her in the master bedroom, Malcolm is shocked by this and Reese agrees and expected Lois to tell both of them "I'm taking you with me!". The two start to suspect something is wrong.
When the fight comes, Lavernia taunts Francis which results in him fighting back and pointing out how much of a sadist Lois really was to him. The fight ends with both of them knocking each other out.
At home the next day, Dewey uses lint from the dryer to cover up Bernard's running away and give to Lance. In the master bedroom, the test results come up negative much to Hal and Lois' relief. Malcolm and Reese later say they know what's going on, thinking that the reason Hal and Lois are so stressed is because they're getting divorced. The two say they completely encourage the idea, and are more than fine with living with Hal while still visiting Lois every now and then. Lois decides to play along, saying that she got full custody of the boys, much to their horror.
- Jane Kaczmerek as Lois
- Bryan Cranston as Hal
- Christopher Kennedy Masterson as Francis
- Justin Berfield as Reese
- Erik Per Sullivan as Dewey
- Frankie Muniz as Malcolm
- Bart McCarthy as Fittsy
- Richard Gross as Dave
- Christopher Michael Moore as Elroy
- Adam Cagney as Lance
- Charles Emmett as a worker
- This is the first appearance of Bernard.
- This is the first appearance of Artie.
- Hal, Dewey and Francis have been shown to have girly pitch screams, while Malcolm and Reese have the masculine screams and Lois having the screams of a banshee.
- After Reese draws a face on the balloon, you see him leaving. While he is leaving you can see the balloon has a totally different face on it.
- While Hal is talking to the fake Malcolm head at night, Dewey and his bright yellow pillow are visibly missing on the opposite side of the bed. In the next consecutive camera angles, Hal pops the fake Reese head balloon and Dewey is seen visibly lying on his yellow pillow while facing the fake Malcolm head.