It is very obvious that Cynthia's chest is nowhere near as developed as in the episode "Cynthia's Return."
We learn that Dewey can play the piano (earlier we learned Francis knows how). This becomes important in a few episodes in the future.
Goof: Malcolm had strapped on the seat belt when he got into the car to carry out his plan. But when Lois pulled him out, there was no unbuckling of the belt.
Malcolm says he was a Krelboyne for four years, but he said later he was a Krelboyne for three years (and he was).
Reese: Stop, I won't let you do this. I'd rather die than be left alone with Mom.
Malcolm: Get out of the way!
Reese: No! You're gonna have to run me over, I don't care. (Malcolm starts car) AAAAAAAHHHHHHHHHHHH! (Reese runs away)
Francis: Otto, we have to talk.
Otto: We will talk tomorrow. Come. I want to show you something.
Francis: No! Tomorrow, I may be leading aerobics again, or faking my way through a wine-tasting seminar, or... or playing the prostitute in the Old West stunt show...
Otto: That was you!
Lois: (to female student)
Fill out both health forms and your emergency contact card. And feel free to button your top. Boys like a little mystery.
Lois: Dewey, come here. Listen, you're going to be coming home from school at 3:00 this year. So, this is the key to the house. You will come straight home, you will let yourself in and you will be in this house alone until your brothers get here exactly 15 minutes later. And not one second more! We're giving this to you because we trust you.
Hal: Congratulations. You're now a latchkey kid.
Lois: It's so exciting being here on the first day of school.
Herkabe: Yes, it's like being at the cockfight, before they open the cages.
Stevie: We joined the chess club.
Lloyd: They love geniuses. I was elected king.
Dabney: I'm the queen, which is actually the more powerful position.
Malcolm: Because... I'm shallow.
Cynthia: (loud enough so everyone can hear) Malcolm, if you do this, I will never have sex with you again!
Final appearance by Tania Raymonde. It was never revealed what happened to Cynthia, her character.
Cold Open: Hal is unable to realize that Francis is giving him money instead of asking for it.
Jordy Masterson is the younger half-brother of Christopher Masterson (Francis).