In the 28th century, Valerian (Dane DeHaan) and Laureline (Cara Delevingne) are a team of special operatives charged with maintaining order throughout the human territories. Under assignment from the Minister of Defense, the two embark on a mission to the astonishing city of Alpha—an ever-expanding metropolis where species from all over the universe have converged over centuries to share knowledge, intelligence and cultures with each other.

There is a mystery at the center of Alpha, a dark force which threatens the peaceful existence of the City of a Thousand Planets, and Valerian and Laureline must race to identify the marauding menace and safeguard not just Alpha, but the future of the universe.