The story follows a group of astronauts on the first mission to colonize Mars, as one of them discovers that she’s pregnant after they’ve already launched. Shortly after the shuttle lands, she gives birth and soon dies from complications, never revealing the identity of her new son’s father.
Sixteen years later, Gardner Elliot (Butterfield) is now a teenager, having spent his entire life on a distant planet and only meeting fourteen other people. Curious about the identity of his father —and the Earth he’s never known— he turns to the Internet, striking up an online friendship with a girl named Tulsa (Robertson), who lives in Colorado.
Gardner and the team of astronauts eventually return to Earth, where he’s eager to begin exploring the home planet he’s never known, only to discover that his organs can’t withstand Earth’s atmosphere. Still curious about his father, he breaks out of medical containment and meets up with Tulsa to continue the search, all while racing against his own failing biology.
