Sador, chief of the Malmoris and a fearsome galactic bandit, approaches the little planet Akir like a conqueror to make a colony out of it. Under the threat of the Stellar Converter, a supremely destructive weapon able to reduce a planet into ashes, he forces the inoffensive people that live in peace on the planet to deliver unto him their next season's crops.
The threat is real. Akirians gather and decide to employ mercenaries to protect them from the tyrant. Shad, a young man determined not to let his people being reduced to slavery, flies off in the only spaceship still on the planet, controlled by a computer with a female voice called Nell. After having escaped Sador's spacecraft, Shad flies off to the Galactic Hand, a region of space where he will be able to meet a "Doctor Hephaestus" to ask him for assistance.
In the orbital station of Doctor Hephaestus, Shad learns that he cannot count on the Doctor's assistance. Worse, the crazed Doctor holds him captive. Shad meets Nanelia, the daughter of the Doctor and an android repairer, who helps him in escaping and joins him onboard a spaceship borrowed from the station.
Back to Akir, Shad crosses a space freighter under attack by space pirates. Coming to the help the freighter, he meets its pilot, Cowboy, an earthling coming from Texas who transports weapons for residents of Oumateale. But the planet Oumateale is destroyed by Sador and his Malmoris by means of the Stellar Converter. Cowboy decides to help Shad and to deliver the Akirians the weapons.
Meanwhile, Nanelia is captured by a spaceship belonging to Cayman of the Lambda Zone, a bounty hunter. Despite complaints from Nanelia, Caïmen decides to sell her. But when she pronounces the name of "Sador" the bounty hunter changes his mind and decides to free and help her. Caïmen has a personal vengeance to accomplish against the tyrant. He knows now where to find him, he knows that he will come on Akir and he will wait for him.
On his way back, Shad meets an alien vessel and welcomes its crew. Nastur, five identical beings that make only one, clones with telepathic and telekinetic powers who knew that Shad was searching for mercenaries. Nastur wants to participate in the fight, because they are annoyed by lack of action against Sador.
On Nell's advice, Shad hires Gelt, a mercenary of the underground city without law; Nascoto. Gelt agrees to work for Shad in return for refuge and food.
Shad, Nanelia, Cowboy, Caïmen, Nastur and Gelt fly to Akir. On their way, they meet a tiny spacecraft piloted by Saint-Exmin, a Valkyrie, who despite the refusal of Shad enters the mercenaries' team. They are now seven and they are going to defend Akir.
The fight is terrible. The tyrant did not expect such a rebellion from these little people. Sador attacks with his drones. Gelt is hit and crashes on the planet. On the ground, Cowboy does his best to repel the ground attack. Nastur (one of the five clones) is made captive. In fact he has sacrificed himself. A ruse that, if it had functioned, would have allowed to put an end to the reign of the dictator. Unfortunately the clone dies in the attempt.
While Sador prepares his fleet for the final attack, Nastur is hit and his vessel explodes. The Stellar Converter is put in position to destroy the little planet. When the magnetic shields are lowered, Santa-Exmin throws her ship into the Annihilator, and then self-destructs. The Cowboy and Caïmen are also victims of Sador and his nuclear missiles. Shad decides then to attack. Although he has destroyed a great number of Sador's missiles, his old "Corsair 6" is damaged. Sador, wanting to get the last defender alive, captures Shad's spaceship thanks to a tractor beam. Shad then prepares the self-destruction of the craft, so that when it happens it will be inside the tyrant's spaceship. Shad and Nanelia eject just in time to see the explosion of the vessel of Sador and with it the liberation of his people. But liberty has a price, the one of a full hand of mercenaries who fought in an exemplary manner.
Of course, this B-movie is a space remake of the famous movies THE SEVEN SAMOURAI from director Akira Kurosawa and its Western version THE MAGNIFICENT SEVEN from director John Sturges. An oppressed people makes call in a band of mercenaries to defend them, having only few things to offer them. The scenario is respected all the long, and the space aspect is grandly present, elsewhere an impressing number of scenes unfold in space. More, James Horner signs the music all simply superb. A captivating movie. An interesting note : Robert Vaughn reprises the role he played in THE MAGNIFICENT SEVEN, a western re-make of the "Seven Samurai".