When Earth astronaut Capt. Chuck Baker arrives on Planet 51 — a world reminiscent of American suburbia circa 1950 — he tries to avoid capture, recover his spaceship and make it home safely, all with the help of an empathetic little green being.

Due to political pressure from the American public, the Air Force has decided to allow two well-known reporters limited access to the most secretive base on the planet. But when one of the base’s “long-term visitors” exploits this unprecedented visit as a chance to liberate himself and his fellow alien captives, Area 51 turns from a secure government base to a horrifying destination of terror.

The world is stunned when a group of time travelers arrive from the year 2051 to deliver an urgent message: Thirty years in the future, mankind is losing a global war against a deadly alien species. The only hope for survival is for soldiers and civilians from the present to be transported to the future and join the fight. Among those recruited is high school teacher and family man Dan Forester. Determined to save the world for his young daughter, Dan teams up with a brilliant scientist and his estranged father in a desperate quest to rewrite the fate of the planet.