Mitt & Minn's Illinois AdventureHardcover, 1 November 2007

After exploring their respective home states, Mitt and Minn meet in Book Three at the Wisconsin Cheese Jamboree. At the conclusion of the exciting cheese-eating contest, they discover that they are indeed brother and sister. A Jersey cow from Illinois shares the news with them and tells them that she can help them reunite with their parents. Mitt and Minn decide against returning to Minnesota with Minn's beloved Gerdie and set off on a new adventure to the land of Lincoln. Will a happy reunion with their parents await the mice there?