Kyeong Sook will do anything to make the world a better place for her son, Cho Won, who has autism. When she realizes that Cho Won enjoys running, she encourages him to enter races. When the young man starts to win some local races, she sets her sights on a marathon for him. She hires a former marathon champion to help train Cho Won. Is the doting mother doing everything she can to help her son achieve his dream – or is she pushing him to do something that she wants for him?