Worried that he won't pass his History Midterm so his dad can take him on a ski trip, Zack talks Screech into helping him create a rodent problem at school so the testing days can be postponed until after his ski trip. Upon learning that his scheme will cause Miss Bliss to taken out of the running for Indiana's Teach of the Year honor, Zack comes forward to tell the truth about what he and Screech did.

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.