Gardner Elliot (Asa Butterfield), a 16-year-old boy who was the first person born on Mars, copes with his isolated existence on the red planet by striking up an online flirtation with a girl who lives in Colorado named Tulsa (Britt Robertson). Gardner eventually decides to travel to Earth in order to meet Tulsa and find out who his father is, only to discover that his body might not be able to handle Earth's gravity.