On the first day of school, Zack is surprised to meet up with a girl with whom he'd had a little summer romance. She was in the 9th grade and he'd lied to her, telling her he was also in the 9th grade. He tries telling her more lies, such as that he has a driver's license and is in a special 9th grade homeroom. He had been elected a class representative, but resigns so that he will not have to appear in front of the assembly as an 8th grader. Miss Bliss catches on and urges him to tell the girl the truth. He finally admits the truth to her, but only after she guesses most of it for herself. She is angry and refuses to have anything more to do with him.

Zack wants Screech to write his history report for him, but Screech will only do it if Zack gets him a date with Lisa. Zack writes Lisa love letters from a secret admirer, and eventually arranges a meeting between Lisa and her secret admirer. This convinces Screech to write the report for him.

Everyone in the class contributed $2.00 each to invest in the stock market as part of a class project with Miss Bliss, buying stock on the internet. Zack is interested in the concept of earning a lot of money with little work involved. He learns just enough that he convinces everyone else to change from investing in an airline to investing in potatoes. This plan backfires because they bought on margin. At first they make a lot of money (about $6,000), but then they lose a lot of money (over $1,000) which means Miss Bliss will have to pay it back, since it's her account. She was just about to buy a new car, but now she won't be able to afford it after paying for the lost investment. Miss Bliss loses her temper and scolds the class. All the kids feel really bad about the whole thing and try to think of ways to pay her back. Miss Bliss thinks of a way. She brings the potatoes to school and wants the kids help her sell them to earn back the money.

The kids have to dissect frogs for a biology class. Nicki is not only squeamish about the dissection process, she doesn't like the idea of all the innocent frogs being killed just for a class activity. She tries to get everyone to support her campaign to free the frogs, but nobody is interested, though Zack and the other kids say they'll lie for her and cover for her if she wants to skip class. She goes to Miss Bliss and Miss Bliss tries to talk the biology teacher into allowing Nicki to abstain from the dissection process, but he refuses. Seeing no other way out, Nicki frees all the frogs.

Meanwhile, Miss Bliss received a letter from an exclusive private school. Mr. Belding assumes they are trying to lure Miss Bliss away with a new job, so he starts being extra nice to her and also giving her all sorts of visual aids and extras (a globe, and encyclopedia set, a VCR & TV, etc.). When Nicki is brought to him to receive her punishment for letting the frogs go free, Mr. Belding sees

Zack and Nicki are in the middle of an argument when Miss Bliss assigns them to work on a project together--to convince people to buy a telephone as though it were a new invention. They do not want to cooperate with each other. Nicki is insistent that they do it her way so Zack backs off and lets her do it her way.

The students are in a frenzy when they learn Stevie (a popular female rock star who was a former student at JFK) will be coming to perform for the kids at the school. Zack makes a bet with the others that he can get a kiss from Stevie. Stevie wants to sing to one special student at JFK. Zack, using his usual sly ways, starts a scheme that leads many, including Stevie, to believe he is dying, so that Stevie will choose to sing to him. Stevie does choose Zack, but when Zack is caught in his lies by Miss Bliss, Screech is given the chance to have Stevie sing to him. Zack, feeling bad about what he has done, goes to Miss Bliss's house to apologize. There he meets Colleen, who is actually Stevie without her rock star get-up on, and who is staying with Miss Bliss while in town. After talking to her for awhile and confessing about his bet, Zack earns a kiss from Colleen. However, Zack leaves Miss Bliss's not knowing he has actually kissed Stevie! During the concert, Stevie approaches Zack

Zack is flattered to be chosen as a pledge by the Rigmas, an exclusive club. Zack is willing to do just about anything in order to get the red jacket that is a sign of club membership. Most of his friends agree that it's worth it, except for Nicki. He has to do some embarrassing tasks and eventually even his friends think it's gone too far.

Meanwhile, Miss Bliss is acting principal for the week, while Mr. Belding takes over her teaching duties, so that she will have the experience necessary to take over if Mr. Belding is ever not there. Miss Bliss loves the job and seems to makes it look too effortless, handling every problem that arises with ease. Mr. Belding, on the other hand, has a lot of difficulty with his teaching duties. He feels even worse when he sees Miss Bliss handling his job so efficiently.