Pepper Mint in the Great Treehouse Engineering AdventureThames & Kosmos Pepper Mint in the Great Treehouse Engineering Adventure In this story based STEM kit, Pepper Mint visits her aunt who is a scientist researching primates. She lives in a treehouse in the rainforest on the island of Borneo. The treehouse is not connected to the electrical power grid, but Pepper Mint and her aunt devise mechanical inventions to accomplish various tasks. They equip the treehouse with mechanical equipment using pulleys,