CREATURE

Two geological researchers for the American multinational corporation NTI find an ancient alien laboratory on Titan, the largest moon of Saturn. In the lab is an egg-like container which is keeping an alien creature alive. The creature emerges and kills the researchers. Two months later, the geologists' spaceship crashes into the space station Concorde in orbit around Earth's Moon, its pilot having died in his seat.

NTI dispatches a new ship, the Shenandoah, to Titan. Its crew, consisting of Captain Mike Davison, Susan Delambre, Jon Fennel, Dr. Wendy H. Oliver, David Perkins and Beth Sladen, is accompanied by the taciturn security officer Melanie Bryce. While in orbit, the crew locate a signal coming from the moon—the distress call of a ship from the rival West German multinational Richter Dynamics. The ground collapses beneath their landing site, dropping the Shenandoah into a cavern and wrecking it. When radio communication fails, a search party is sent out to contact the Germans.

In the West German ship, they find the egg-like container and the dead bodies of the crew. The creature appears and kills Delambre when she lags behind the escaping group. Fennel goes into shock at the sight and Bryce sedates him. When they return to their own ship, the Americans find that one of the West Germans, Hans Rudy Hofner, has snuck aboard. He tells them his crew was slain by the creature, which was buried with other organisms as part of a galactic menagerie. He proposes returning to his ship to get explosives, but the crew are unwilling to risk it.

The creature's undead victims are controlled by the creature through parasites. Unsupervised in the medbay, Fennel sees the undead Delambre through a porthole and follows her outside. She strips naked, and he stands transfixed while she removes his helmet. He asphyxiates, and then she attaches an alien parasite to his head. Now under alien control, Fennel sends a transmission to his crewmates, inviting them over to the German ship. Hofner and Bryce are sent to get some air tanks for the Shenandoah and stand guard over it, while the rest of the crew go over to the Richter ship. Hofner and Bryce stop over at the menagerie on their way, and are attacked by Delambre. The rest of the crew find Fennel with a bandage on his head to conceal his parasite. Davison insists that medical officer Oliver examine his head, so Fennel has her accompany him to the engineering quarters to feed her to the creature. Davison and Perkins notice Fennel does not sweat and go check on them. They find Oliver has been decapitated by the creature. Perkins blows up Fennel's head with his pistol.

Sladen runs into an infected Hofner. She escapes the ship, and in her haste, only puts on her helmet after exiting. Perkins spots her outside and opens the airlock. Now unconscious, Sladen is carried in by Hofner to lure the others. They fight, and Davison defeats Hofner by ripping off his parasite. The three survivors formulate a plan to electrocute the creature with the ship's fusion modules, which can only be accessed by going through the engineering quarters.

Alarms sound as a creature makes its way through the ship, committing sabotage. Sladen and Davison construct the electrocution trap, while Perkins goes to the computer room to monitor the creature. The creature arrives, and they apparently electrocute it to death. However, when Davison leaves, it captures Sladen.

Davison and Perkins follow her screaming and find her locked inside engineering. Studying the ship's blueprints, they find another entrance to engineering. Perkins lures away the creature while Davison retrieves Sladen. On the way, Perkins locates one of the bombs Hofner mentioned. The creature jumps him. Dying, Perkins attaches the bomb to the creature and sets a countdown so Davison can jettison it through the airlock. It climbs back aboard, however, so Davison tackles it, throwing himself out the airlock. When the bomb fails to explode, Bryce appears and shoots it, which sets it off and kills the creature. She recovers Davison and reunites with Sladen, who dresses Davison's wounds. The trio leaves Titan aboard the West German ship.

The survivors use electricity to destroy the alien creature and manage to escape Titan, leaving the threat neutralized for now.

The film concludes with the remaining characters overcoming the alien menace through ingenuity and teamwork, emphasizing that the human will to survive persists even in the face of corporate greed and cosmic danger. The defeat of the creature serves as both a physical and symbolic closure to the cycle of violence unleashed by meddling with unknown extraterrestrial forces.