Andy is working on his resume when a neatly-dressed Nick comes in and announces that he's working as a substitute teacher. Unfortunately, he doesn't have a car and is dependent on Joel for a ride. He returns the favor by spitting food in his clean car.
When Nick arrives at school, he first dispels all the rumors about cavemen then catches the students' attention with his… elaborate theories on history and business. Meanwhile, Kate's mom, Leslie, drops in after finding Andy's resume in the photocopier. After mistaking him for Joel, she finally asks him to work for her as an accountant and he agrees.
Nick thinks he's finally found his calling as a teacher and is glad to share it with the other teachers (while stealing their food), but then he discovers that the school mascot is… a caveman. He goes to Principal Collins, but while she "hears him" she's not interested in changing the traditional mascot, and convinces him it's a symbol of pride and dignity.
Nick partners up with Maurice to play squash against Joel and Andy, and Andy ends up telling Joel that Leslie is embezzling money from her husband to afford a condo for her lover. Andy is now relieved to get the secret out, but now Joel is stuck with it. He has coffee with Kate and asks about her parents, but as far as she knows of they're doing fine. Joel quickly asks some other questions to cover for his interest, but can't bring himself to tell her.
Nick finishes class at the high school but discovers that the students have spirit clubs for the homecoming game. He's not happy.
Joel goes to Leslie, who mistakes him for Andy. Once he explains who he is, he asks her to be honest with Kate or he'll have to tell his girlfriend himself. Leslie agrees to tell her daughter about the situation.
Nick goes outside to watch the rally and comes face to face with the mascot, complete with a dog dressed as a stegosaurus. He asks the mascot to stop but when it mocks him, he finally ends up knocking it down. It turns out a girl is wearing the suit and everyone in the school hates him for beating up on her. Since he still doesn't have transportation, Maurice gets him out of there before the scene turns ugly.
The guys have a beer and Andy is relieved that he doesn't have the secret any more. Nick figures he's okay because just a couple of hundred students saw him beat up a girl… until he discovers someone took the video and put it on the Internet. However, Leslie stops by and, thinking he's Joel, bribes him to keep the embezzling a secret. Nick bargains for $2,000 and uses the money to buy a motorbike: he finally has transportation.