It's the Harvest Festival week at school and Miss Bliss' class is intent to be the class to finally prank their favorite teacher, only to have Mr. Belding be their unintended victim with each attempt. However, when it finally looks like someone was able to prank Miss Bliss, Screech is wrongfully accused and put on trial.

Zack is thrilled when a cool club asks him to pledge their club. While going through their grueling "pledge week," Zack almost loses his friends when he refuses to say enough to their whims, only to get heartbroken at discovering his invitation is only part of a prank. Meanwhile, Mr. Belding is in for a rude awakening when he subs for Miss Bliss while she fills in as acting principal for a week.