Growing up in post-World War II era Arizona, a young man named Sammy Fabelman (Gabriel LaBelle) finds a love of film when his parents (Michelle Williams, Paul Dano) take him to see his first movie. Obsessed by the train crash in the film, he asks for a train set so he can recreate the crash on home video.

He continues to make films with his friends and even figures out how to do special effects using different techniques. When Sammy is in his teens, he discovers a shattering family secret after viewing a home movie he made while on a trip.

Based on director Steven Spielberg's formative years.