In the months after losing his father, 9-year-old Sam Collins retreats into his imagination as he works through his feelings of grief. The film explores the role of childlike wonder and imagination in contemplating death and what happens to people when they die. Sam spends hours in a make-believe spacecraft in his bedroom where he pretends to explore the galaxy. After finding a radio in the basement of his house, Sam meets a young girl, Marie, who lures him out of his isolation and inspires him to make contact with the International Space Station.