Mister Conductor's sister visits him at the station. At that same time, Kara's grandfather, Harry, also comes for a visit. He builds a small race car for Kara and wishes that she would participate in the annual race. However, Kara has other plans and does not want to do everything that Harry wants her to do. Meanwhile, Mister Conductor gets very upset when his sister uses her magic to play tricks on people. During the day of the race, Kara thinks about how she has been unfair to Harry, so she decides to participate in the race at the last minute. Unfortunately, a wheel on her car breaks. Sister Conductor decides to help while she and Mister Conductor fly on a plane and they drop a useful tool in Kara's pocket. Kara uses the tool to fix her car, and she manages to win the race. At the end, she dedicates the trophy to her grandfather.