Sarah Jane Hartwell and her class are back. After the stress of her last attempt at taking her class on a field trip (seen in First Year Letters), Mrs. Hartwell has a plan for an upcoming trip to the zoo—a plan that includes a lot of rules. Her students prove that they can line up straight, walk quietly, and take plenty of notes, but everyone soon realizes that this field trip isn't as much fun as they'd hoped. Mrs. Hartwell rethinks her plan and saves the day.