Entering the latest Mystery train car, Wendell and his friends meet three legendary heroes, selfless and dedicated to protecting the Residents of this land from an evil they accidentally released. Shocked to find out that these heroes are human Visitors who have long earned their Zeroes and a door back to their original forms, Wendell must try to help defeat the evil running rampant in the Hero Car to absolve these weary paragons of their self imposed duty. However, a grim truth comes to light that threatens to shake up everything Wendell has come to understand about the Infinity Dungeon Train…