Zack and Kelly are both looking forward to their upcoming nuptials. Unfortunately, Kelly finds out that her parents aren't going to give them any financial help, so they are on their own. Zack goes to Slater and Screech and asks for their help in getting the wedding together, and Slater surprises him by saying that he thinks the marriage is a mistake and he wants nothing to do with the wedding. In retaliation, Zack makes Screech the best man.
Later, both Leslie and Alex ask Zack if they can be Kelly's maid of honor, and he makes the mistake of telling them both that they can. Things get even more complicated when Lisa shows up, and of course she plans to be the maid of honor as well.
Things go from bad to worse when Zack and Kelly find out that the chapel is booked for the next six months, and that they would need Dean McMahon's permission for them to live off campus. However, a visit to the Dean solves both problems, as she realizes that marriage would certainly force Zack to drop out of school, so she gives them permission to live off campus and gets them the chapel for that weekend. The only hook is that they will have to meet with Reverend Dunlap to prove that they're ready for marriage.
Screech brings Zack and Lisa to meet with a ring salesman, who is obviously a two-bit crook. Everything he shows them is junk except for the ring on his finger, and Lisa talks him into selling it for $600. Then Zack takes Kelly to the only apartment he was able to afford. It turns out to be an absolute dump that it would be a nightmare to live in. Frustrated by the whole experience, Zack pours out his heart to Slater, who says that he can help fix up the apartment. Zack is surprised to hear this, but is happy that Slater is still his friend and finally wants to be a part of the wedding.
Slater takes over the plans for the bachelor party from Screech, and he plans a wild party. Meanwhile Leslie, Alex, and Lisa put an end to their feud over who's going to be the maid of honor and decide to put on a bachelorette party for Kelly. And as Zack and Kelly wait for their meeting with the reverend, they're surprised by both parties converging on them. Unfortunately, Reverend Dunlap walks in in the middle of it and refuses to marry Zack and Kelly as he considers them too immature.
Everything has fallen apart, and Zack feels that the whole situation is hopeless, but Kelly makes it clear that she still wants to marry him and that they could just drive over the state line and get married in Reno, Nevada. Zack decides that they should get married, but in Las Vegas instead.