In the 28th century, due to cooperation between the Earth’s countries (beginning with the ASTP of 1975) and extraterrestrial peoples, the former International Space Station has been expanded until its mass threatens to cause it to fall out of orbit. Relocated to deep space using thrusters, it becomes Alpha, a space-traveling city inhabited by millions of species from thousands of planets. A special police division is created by the United Human Federation (a world government formed by a federation of Earth’s countries) to preserve peace through the galaxy, including happy-go-lucky Major Valerian and his partner, no-nonsense Sergeant Laureline.
En route to a mission, Valerian dreams of a planet, Mül, where a low-tech humanoid race lives peacefully. They fish for pearls containing enormous amounts of energy, and use small animals to replicate them. Wreckage begins plummeting from the sky, followed by a huge spacecraft that falls and causes an explosion that annihilates every living being on the planet. Some of the sentient inhabitants enter a discarded vessel and accidentally trap themselves inside, but the planet’s young princess Lihö-Minaa is stranded outside. Just before her death, she conveys a telepathic message.
Shaken, Valerian awakes. After an argument with Laureline regarding their relationship, analysis reveals he might have received a signal from across time and space. He learns that his mission is to retrieve a “Mül converter,” so-called for being able to replicate anything it eats. It is the last of its kind, and currently in the hands of black market dealer Igon Siruss. Before setting out, Valerian asks Laureline to marry him, but she brushes him off due to his aversion to commitment and his numerous affairs with colleagues.
On planet Kirian, Valerian disrupts a meeting, in a zone forbidden to humans, between Igon and two hooded figures who resemble the humanoids from his vision. They also seek the converter, the small animal in his vision. Valerian and Laureline recover the converter and surreptitiously steal one of the energy pearls. Aboard their ship, Valerian learns that Mül was destroyed 30 years earlier, and all information about it is classified.
They return to Alpha where the frosty station commander, Arün Filitt, informs them that the center of the station has been invaded by an unknown force, rendering it highly toxic. Troops sent into the area have not returned, and the infection is growing. Laureline and Valerian are assigned to protect the commander during an interstation summit to discuss the crisis; against the commander’s wishes, Laureline maintains possession of the converter.
During the summit, unidentified humanoids suddenly attack, incapacitating everyone and kidnapping Filitt. Valerian chases the kidnappers on foot, in his spacecraft, and then in his Lexus SkyJet aircraft to the infected area and crashes the plane. Desperate for news of her partner and evading arrest for insubordination, Laureline enlists opportunistic aliens’ help to track Valerian, and finds him unconscious at the edge of the infected zone. She rouses him, but is kidnapped by a primitive tribe, the Boulan Bathors of the planet Goara whose colony is nearby, and presented at their emperor’s dinner as the choice course. Valerian infiltrates the tribe’s territory with the help of the shape-shifting Glamopod entertainer Bubble, who he met in the red-light district, Paradise Alley. They rescue Laureline and escape, but Bubble is wounded. Near death, she tells Valerian not to give up on his feelings for Laureline.
Valerian and Laureline venture further into the infected area, discover it is not toxic, and that it contains the remains of some antique spacecraft. They reach a large shielded hall where they find the humanoids, known as the Pearls, with an unconscious Filitt. The Pearls’s leader, Emperor Haban Limaï, explains that his people lived peacefully on Mül until an orbital battle occurred between the Federation and a faction known as Southern Territories. Filitt, the human commander, ordered the use of three powerful fusion missiles that disabled the enemy ship and sent it crashing into the planet, annihilating Mül. Upon her passing, Princess Lihö-Minaa transferred her soul into Valerian’s body.
When the surviving Pearls were trapped in a downed space vehicle from the battle, they managed to repair it and learned the humans’s technology and history. They eventually came to Alpha, helped by some merchants, where they assimilated more knowledge and built a ship of their own by stealing parts from Alpha’s various civilizations. They needed only the converter and the pearl to launch the ship so they could find a planet to use their technology to recreate their homeworld. Filitt admits his role in the genocide, but argues it was necessary to end the war—as was the coverup, to prevent humans from being expelled from Alpha. Valerian and Laureline disagree, arguing that the commander is trying to avoid the consequences of his actions. When Filitt becomes belligerent, Valerian knocks him out.
Valerian hands over the pearl he stole, and Laureline persuades him to return the converter too, despite their orders. While the Pearls prepare their spacecraft for takeoff, Filitt’s pre-programmed K-Tron robot soldiers attack the Pearls, the government soldiers sent to assist Valerian, and their support staff, but are ultimately defeated. The spacecraft departs and Filitt is arrested. Valerian and Laureline are left adrift aboard a still-working Apollo Command/Service Module identified by radio technicians as Destiny 2005, and Laureline finally answers Valerian’s marriage proposal with a “maybe” as they wait for rescue.
As the weather was lovely today, I caught up with laundry, what it with blowing on the line and the sunshine, it was soon dry.