Take a journey with Little Mouse. She's a pure, sweet young mouse who follows the advice of Elder Mouse and the Authorities in the Marketplace. She knows her place, wants to serve, and cannot understand why anyone would go through the Purple Door. Why would anyone leave the One True Village, where everyone is safe, the rules are clear, and they follow The True Mouse Way? Little Mouse finds out a friend has gone through The Purple Door and into The World. Then, she receives a mysterious key. The actions of the Elders and Authorities push Little Mouse to rethink her world and her belief in the safety and rightness of the One True Village.