Plot summary
Wirt, Greg, Beatrice, and the frog come across a primary school with animals as students. The human teacher, Miss Langtree, mistakes Wirt for a student. All she teaches them is about how the man who was courting her left her. Greg plays outside with other animals until they all retreat into the school to escape a gorilla. At mealtime, Greg tries to cheer everyone up by singing and adding molasses to their bland mashed potatoes. The meal is interrupted by Miss Langtree's father, the school's founder. He confiscates their musical instruments and sends them all to bed.
In the night, Greg and Wirt sneak out and find Mr. Langtree camping in the woods. They hear him lament that he will have to sell the instruments to continue funding the school. When Mr. Langtree wakes, he finds Greg and Wirt have organized a benefit concert, which raises enough money to keep the school open. The gorilla appears again and Wirt trips and falls into it, revealing that the gorilla is Miss Langtree's missing beau wearing a costume, having joined the circus to earn money for an engagement ring.
Credits
Adapted from Wikipedia contributors, Over the Garden Wall. Exact series, overall episode number and English title matched. Reference markers and illustrations removed; paragraph formatting adjusted.