Sophie is a lonely girl in her teens, who lives a secluded life with her father. After she finds a scorched baseball in her garden, she goes looking for the original owner. When the mysterious Alex shows up, looking for his baseball, Sophie recognizes the boy from one of her mother's bedtime stories. Alex claims to live on the moon and asks Sophie to come with him. When Sophie mentions this encounter to her father, he calls in a doctor who is convinced she is delusional. Fearing she is going to be put on medication, Sophie runs away with Alex...