露斯從醫生口中得悉自己患上白血球病，難以接受真相的她愈是不能馬金，卻愈是不得已的與馬金同被困在一密室中相處。另邊廂，夏爾則忙於出席附近的俾面派對。

Lois discovers she has mono after a visit to the doctor. She then ends up giving it to Malcolm after her maternal instincts begin. As a result, both Lois and Malcolm are forced to spend an entire day and night together in the same room. Hal, meanwhile, is invited to all of his neighbors' parties after they know Lois will not be attending any of them.

夏爾與其生父一直都鮮有聯絡，對他的認識近乎零，故此當他知道父親離世後，沒有半點傷心，猶如沒發生過一樣。經此一役，夏爾突然一反常態，准許大家曠課一天，任意妄為；又送馬金一輛新車，令眾人對夏爾的行徑摸不著頭腦。露斯發現事情的嚴重性，遂一聲令下，停止了大家的興奮心情……

Hal learns that his father has passed away, but sheds no tears and passes it off as nothing since he never knew him. So, to make sure nothing like that happens again, he lets the boys do whatever they want by letting them miss school and even offering to buy Malcolm a new car, until Lois puts a stop to it. Noticing how depressed Hal has become, his friend Abe brings George Takei over for a visit in an attempt to cheer him up.

露斯與夏爾往探訪Francis，慶祝他戒酒一周年。但當三人一起參加一個聚會時，才驚悉當初是露斯讓Francis開始飲酒。另邊廂，Dewey回到家裡發現了夏爾的車匙，遂不斷要求馬金、列斯等人開車帶他去逛街。二人最後會否答應？

Francis receives a visit from Lois and Hal to celebrate his one-year anniversary of sobriety. However, when they attend one of his A.A. meetings, it's revealed that it was Lois who forced him to start drinking. Back home, Dewey finds Hal's spare key for his car and tries to get Malcolm and Reese to drive him to the arcade, but, of course, they refuse.

校內四個受歡迎的女生針對列斯，製造惡作劇，向眾人宣揚列斯有一位神秘的傾慕者。及後露斯出現救了列斯，並打算向四位女生報復。另邊廂，夏爾認為露斯是名危險人物，會影響他的計劃，遂設法遠離她。

When four popular high school girls play an evil prank on Reese by pretending he has a secret admirer and then dropping a pig off at his front door, Lois comes to his rescue. She plots her revenge on the four unsuspecting girls and wreaks havoc on their adolescent lives. Meanwhile, Hal realizes Lois is at a dangerous emotional place so he decides to get some distance and stumbles upon the idea for making his own pitching machine out of stuff in the garage.

夏爾朋友Trey因為玩遊戲掉了牙齒，要到夏爾的診所求助，夏爾當然義不容辭，奈何在最後時刻因為收費問題令二人反目，雙方友誼備受考驗。另邊廂，列斯教露斯踏單車，而馬金和Dewey則開始覺得睡覺是他們最好的消遣活動。

Hal's friend Trey tells him to come to his dental office when he looses a tooth during a poker game, but their friendship becomes in jeopardy when Hal's faced with a $2,000 bill and causes a fight between them. Reese, meanwhile, teaches Lois how to ride a bike, while Malcolm and Dewey find sleeping as their new favorite pastime.

馬金走去學人跳舞，還要報名比賽；無他，目的只有一個，就是為了吸引一位女孩子。其後，馬金明白到如果要勝出比賽，就得跟一位高手好拍檔，助他出線。另外，舞蹈班中有一位學生Dick對跳舞比賽十分緊張，並決定要向馬金挑戰，將他打敗。

Malcolm joins a local dance class to impress a girl, but when she loses her footing, he realizes that to win the competition he'll need a partner who can step it up. Dick, a rival student in the class who takes dancing a bit too seriously, challenges Malcolm to a dance-off. Meanwhile, Hal discovers an underground bachelor pad in the backyard.

Stevie卻帶馬金往醫院去，但馬金不知何故總是迴避，偣辭推搪。另邊廂，夏爾沉迷於他的新玩意－搖控模型船；露斯的精神狀態開始有點失常。

When Stevie goes to the hospital, Malcolm tries making up every excuse he can think of to not go because he can't face the truth about his illness. Meanwhile, back home, Hal gets highly competitive about his new remote control boat, while Lois thinks she's going insane.

馬金為了一群被遺棄的兒童在學校舉行舞會，同一時間，列斯也舉行派對；然而，兩者的目的卻大相逕庭。

Malcolm organizes the outcast kids at school for an anti-prom; Reese is transformed into the perfect prom date… for a price; and Dewey holds Hal's wallet hostage for the attention he was denied as a child.

第七輯《左大做人難》今晚大結局。馬金被選為畢業典禮上致告別辭的學生代表，為了演辭的虛假，他內心掙扎，但露斯卻難理馬金牢騷。另邊廂，為了獲得高校警衛這份長工，列斯不惜一切。露斯進行驗孕，並向夏爾展示結果，夏爾嘩然……

Malcolm is elected valedictorian of his graduating class and struggles with his speech, but Lois refuses to hear his complaints. Reese and Craig move in together. Reese will do anything to get a permanent job as the high school janitor and he fights his way into the position. He concocts the most disgusting mess of all time, which explodes all over the family. Lois takes a pregnancy test and shows it to Hal, who screams.



又做完！