T.S. Spivet lives on a remote ranch in Montana with his parents, his sister Gracie and his brother Layton. A gifted child with a passion for science, he has invented a perpetual motion machine, for which he has been awarded the prestigious Baird Prize by the Smithsonian Institution in Washington. He leaves a note for his family and hops on a freight train to make his way across the United States and receive his prize. But no one there suspects that the lucky winner is a ten-year-old child with a very dark secret...