At Dartmoor Academy snooty principal Morgan Brinway (BD Wong) has second-graders studying opera appreciation, but five feisty kids, nicknamed the "Stinkers" by Brinway, skip class to create chaos on the school grounds. Although they get a warning from Brinway, they soon rebel with more misadventures. Discovering sea lion Slappy during an aquarium field trip, they smuggle him back on the school bus and install him in Brinway’s hot tub. Groundskeeper Roy (Bronson Pinchot) mistakes the sea lion for a giant gopher and plans to kill him, but before that can happen, animal thief Boccoli (Sam McMurray) makes off with Slappy, planning to sell him to the circus — prompting the Stinkers to set forth on a rescue mission.