A dance contest is hosted by famed Casey Kasem and held at the Max. Zack and Slater both try to obtain Kelly as a dance partner but Slater wins the honor. Zack goes with Jessie. Lisa has someone all lined up for the dance as well, but when she sprains her ankle he backs out. Screech agrees to dance with her in the contest even still. Screech and Lisa win the contest with a new dance known as the "sprain."
Screech is struck by lightning in a freak accident. As a result, Screech can see into the future. Zack and Slater begin to bet on things in the future; Zack uses Screech's ability to see into the future to give him the edge in the bets. Screech tries to predict the questions to a school test but proves unsuccessful in this endeavor.
Kelly has to choose between Zack and Slater to go to a big dance Bayside is having. Zack wants to make sure that he is Kelly's choice. In order to do that, he places a microphone in Jessie's room before her slumber party, which Kelly will be attending. Soon, Jessie discovers the microphone and Kelly comes up with a plan to play a trick on Zack, making him believe that she is a very dangerous soul.
Zach tries desperately to find Screech a woman so that he will concentrate on their science project but keeps on failing. Zack then comes up with the brilliant idea of posing as a woman over the phone to Screech. Brilliant that is, until Screech wants to meet his mystery woman and things get a little bit out of hand.
Slater has to decide rather or not he and his dad are going to move to Hawaii or stay in Bayside. It is interesting that Slater's dad lets him decide this but seems unconcerned with Slater's thoughts on his future later on (wrestling scholarship or the army.) Zack at first tries his best to convince Slater to move away, so that Zack can get rid of his best rival for babes. Zack changes his mind though and Slater stays in Bayside.
Zack and Jessie are both running for class president. Zack decides to run only because he found out the winner of the election gets a trip to Washington D.C. Slater overhears Zack telling Screech about this, so Slater tells Mr. Belding about it. Mr. Belding tells Zack the trip was canceled--and that the only way Zack can prove he wasn't running just to get the trip is to stay in the election. Zack was ahead, but now he tries to lose. In the end he wins anyway, but Jessie is so upset that he confesses to her and promises to tell Mr. Belding the truth and resign the presidency in favor of Jessie.
Zack falls for a college girl named Danielle when she goes to The Max to use the phone. In order to impress her, he lies about his age and makes fake I.D.'s so that that he, Slater and Screech can sneak into an over-18 nightclub. However, they get a big surprise when they see Kelly's boyfriend Jeff dancing with another girl there.
Jessie meets her new stepbrother, Eric, but soon discovers that he has a dark side to him as he uses blackmail to get his way. Meanwhile, Eric takes a liking to Lisa, and Zack and Slater decide to get their revenge on Eric by setting him up to get caught driving Mr. Belding's shiny new red convertible. Things go awry, however, when Eric lets Lisa drive the car and she gets into an accident.
Eric learns that Zack and Slater paid Lisa off to go out with him in order to get him into trouble for driving Mr. Belding's car. To get back at them, Eric has the auto mechanic class take the totaled car apart. When Jessie finds out she confronts him about it, and soon gives him a black eye for calling her a "chick." To make amends, Eric puts Belding's car back together himself so Zack and Slater do not get into trouble, and apologizes.
In this conclusion of the long running series it finally happens: Kelly and Zack will marry. Zack's parents are against the early commitment and Kelly's parents can't afford it, so only the gang travels to Las Vegas for the wedding. However, before the wedding can happen, they have to live through many adventures, including Zack losing his hard earned money, Kelly becoming jealous and Slater being chased by mobsters.